Section 45 Evidence Act vs Section 39 BSA: Expert Opinion, 'Any Other Field' and the Electronic Evidence Examiner

In India, Section 39 of the Bharatiya Sakshya Adhiniyam, 2023 (BSA) replaced Section 45 of the Indian Evidence Act, 1872 (IEA) from 1 July 2024. Section 39(1) keeps expert opinion a "relevant fact" and adds "or any other field". Section 39(2) carries over old Section 45A on the Examiner of Electronic Evidence, unchanged in substance.

At a glance

	Old law	New law
Section	Sections 45 and 45A, Indian Evidence Act, 1872	Section 39(1) and (2), Bharatiya Sakshya Adhiniyam, 2023 (in force from 1 July 2024)
What it does	Expert opinion on foreign law, science or art, handwriting or finger impressions is a relevant fact (s.45); so is the Examiner of Electronic Evidence's opinion (s.45A)	Same, plus "or any other field" (s.39(1)); s.45A becomes s.39(2)
Punishment	None. A rule of relevancy, not an offence	None. A rule of relevancy, not an offence
Cognizable / bailable / triable by	Not applicable (no CrPC First Schedule entry)	Not applicable (no BNSS First Schedule entry)
Change type	—	Expanded (s.39(1)); carried over with a drafting change (s.39(2))

What changed

Fields covered — Expanded. "a point of foreign law or of science, or art" becomes "a point of foreign law or of science or art, or any other field". The persons whose opinions are relevant change from those "specially skilled in such foreign law, science or art" to those skilled "in such foreign law, science or art, or any other field".
Punctuation — Minor edit. The comma after "science" in the first phrase ("science, or art") is dropped.
Closing words — Minor edit. The separate sentence "Such persons are called experts." becomes part of the section: "are relevant facts and such persons are called experts".
Handwriting and finger impressions — Identical in substance. Both limbs stay. In the IEA the words "or finger impressions" were inserted by Act 5 of 1899 (s.3), and "or in questions as to identity of handwriting" by Act 18 of 1872 (s.4).
Illustrations (a)–(c) — Identical. Death by poison, unsoundness of mind, and whether two documents were written by the same person.
Examiner of Electronic Evidence — Minor edit (moved). Section 45A, inserted by Act 10 of 2009, s.52 (w.e.f. 27-10-2009), becomes s.39(2). Its words are repeated. The parenthesis "(21 of 2000)" after the IT Act moves to the margin note.
Explanation to the Examiner provision — Minor edit. "For the purposes of this section" becomes "For the purposes of this sub-section". The rule that "an Examiner of Electronic Evidence shall be an expert" was already in s.45A; it is carried over, not created.
Linked provisions — Identical. IEA s.46 (facts bearing upon expert opinions) is BSA s.40, and IEA s.51 (grounds of opinion) is BSA s.45, word for word, illustrations included.

Statutory text (relevant extract)

Section 45 IEA — extract (illustrations omitted):

When the Court has to form an opinion upon a point of foreign law or of science, or art, or as to identity of handwriting or finger impressions, the opinions upon that point of persons specially skilled in such foreign law, science or art, or in questions as to identity of handwriting or finger impressions are relevant facts.

Such persons are called experts.

Section 45A IEA — full text:

When in a proceeding, the court has to form an opinion on any matter relating to any information transmitted or stored in any computer resource or any other electronic or digital form, the opinion of the Examiner of Electronic Evidence referred to in section 79A of the Information Technology Act, 2000 (21 of 2000), is a relevant fact.

Explanation.—For the purposes of this section, an Examiner of Electronic Evidence shall be an expert.

Section 39 BSA — extract (illustrations omitted):

(1) When the Court has to form an opinion upon a point of foreign law or of science or art, or any other field, or as to identity of handwriting or finger impressions, the opinions upon that point of persons specially skilled in such foreign law, science or art, or any other field, or in questions as to identity of handwriting or finger impressions are relevant facts and such persons are called experts.

(2) When in a proceeding, the court has to form an opinion on any matter relating to any information transmitted or stored in any computer resource or any other electronic or digital form, the opinion of the Examiner of Electronic Evidence referred to in section 79A of the Information Technology Act, 2000, is a relevant fact.

Explanation.—For the purposes of this sub-section, an Examiner of Electronic Evidence shall be an expert.

How it works — the steps and the illustrations

A point on which the Court "has to form an opinion" (s.39(1)). The point must be one of foreign law, science or art, "any other field", or identity of handwriting or finger impressions. The illustrations give three worked examples: symptoms of a poison (a), unsoundness of mind (b), and comparison of a disputed document with one proved or admitted to be A's (c).
A person "specially skilled" on that point. The Act does not define the phrase. In State of H.P. v. Jai Lal the Supreme Court read it to require a witness who "has made a special study of the subject or acquired a special experience therein".
The opinion is a relevant fact, not proof. Whether a fact is "proved" remains for the Court under s.2(1)(j); the opinion is one input.
The grounds matter as much as the conclusion (s.45). When an opinion is relevant, "the grounds on which such opinion is based are also relevant". The illustration: an expert may give an account of experiments performed to form the opinion.
Other facts can support or undercut the expert (s.40). Facts not otherwise relevant become relevant if they support or are inconsistent with a relevant expert opinion.
Electronic information (s.39(2)). Where the Court must form an opinion on information transmitted or stored in any computer resource or other electronic or digital form, the opinion of the Examiner of Electronic Evidence is a relevant fact. Under s.79A of the IT Act, the Central Government may, by notification in the Official Gazette, specify a Department, body or agency of the Central or a State Government as an Examiner.
Other routes for handwriting and signatures. Besides an expert, the Court may rely on a person acquainted with the handwriting (s.41(1)), on the Certifying Authority's opinion as to an electronic signature (s.41(2), formerly IEA s.47A), or on its own comparison of the writings (s.72, formerly IEA s.73).

What this means in practice

For the party calling an expert. Prove the special skill first: qualifications, study and experience in the precise question. Then put the reasons, data and any experiments before the Court (s.45); an unexplained conclusion failed in Jai Lal.
For opinions from newer disciplines. On a reading of s.39(1), "any other field" removes the need to argue that a discipline is "science" or "art". It does not lower the threshold of special skill. In Ramesh Chandra Agrawal (para 11) the Supreme Court listed, from a textbook, three further requirements: a recognised field of expertise, evidence based on reliable principles, and an expert qualified in that discipline.
For the opposing party. Cross-examine on the data and method, not only on qualifications. Section 40 lets you lead facts inconsistent with the opinion, and you may call your own expert.
For prosecutors and investigating officers. Section 329 BNSS (formerly s.293 CrPC) lets a report of a listed Government scientific expert (for example a Chemical Examiner or a Forensic Science Laboratory director) be used as evidence, subject to the Court's power to summon the expert. Section 329(4)(g) now covers any other scientific expert "specified or certified, by notification, by the State Government or the Central Government"; s.293(4)(g) CrPC covered only a Government scientific expert specified by the Central Government. Under the second proviso to s.330(1) BNSS, no expert is called unless a party disputes the report, and s.330(1) sets thirty days from supply (relaxable) for admitting or denying documents, so the defence must dispute a report in time.
For electronic evidence. Keep s.39(2) and s.63 apart. The s.63(4) certificate is signed by the person in charge "and an expert" (Schedule Part B, "To be filled by the Expert"); the Act does not say whether that expert must be a s.79A Examiner. A s.39(2) opinion goes to the information once the record is before the Court.
For any document-based opinion. Prove the document itself. In C. Kamalakkannan (para 13) the expert's report became "redundant" because the original postal cover he had examined was never exhibited.

Judgments that still matter

BSA s.39 repeats the operative words of IEA ss.45 and 45A (adding "or any other field"), so on a reading of the text judgments construing them remain relevant. None below construes s.39 itself.

Murari Lal v. State of Madhya Pradesh, [1980] 2 S.C.R. 249, decided 21 November 1979. O. Chinnappa Reddy J. delivered the judgment of a two-judge bench (with R.S. Sarkaria J.). A handwriting expert had attributed a note left beside the deceased to the appellant. The Court held "that there is no rule of law, nor any rule of prudence which has crystallised into a rule of law, that opinion evidence of a handwriting expert must never be acted upon, unless substantially corroborated". The approach must be cautious and the reasons probed; and s.73 IEA lets the Court compare writings itself, which is its "plain duty" where needed. The appeal was dismissed. The report carries no paragraph numbers; C. Kamalakkannan quotes this passage as para 11. Why it matters now: the handwriting limb of s.39(1) and the comparison power in s.72 BSA are unchanged.

State of Himachal Pradesh v. Jai Lal, [1999] Supp. 2 S.C.R. 318 (1999 INSC 393), decided 13 September 1999. D.P. Mohapatra J. delivered the judgment of a two-judge bench (with K.T. Thomas J.). The prosecution's case of inflated scab-apple purchases rested on a horticulture officer's yield assessment. The Court held that "An expert is not a witness of fact. His evidence is really of an advisory character." Credibility depends on the reasons and data given, and the report "does not go in evidence automatically" (report p. 325). The officer showed no study of apple productivity and inspected the orchards only the following year; the acquittals were upheld (pp. 326–327). Why it matters now: "specially skilled" is repeated in s.39(1), and the test applies equally to "any other field".

Ramesh Chandra Agrawal v. Regency Hospital Ltd., [2009] 14 S.C.R. 424 (2009 INSC 1131), decided 11 September 2009. H.L. Dattu J. delivered the judgment (with G.S. Singhvi J.) in a medical-negligence complaint. It said the first requirement for expert evidence is that the matter is outside the knowledge and experience of the lay person (para 11). It set out Jai Lal's reading of s.45 (para 13), repeated (citing Malay Kumar Ganguly) that an expert is not a witness of fact and that his evidence is advisory (para 15), and noted that no reliance can be placed on an opinion alone without examining the expert as a witness (para 16). Because the expert had not been sent the original records and X-ray films, the matter was remitted for a fresh opinion (para 27). Why it matters now: the para 11 criteria are the obvious starting point for testing an expert in "any other field".

Anvar P.V. v. P.K. Basheer, [2014] 11 S.C.R. 399 (2014 INSC 645), decided 18 September 2014. Kurian Joseph J. delivered the judgment of a three-judge bench (with R.M. Lodha CJI and R.F. Nariman J.). On the relationship between s.65B and s.45A the Court said: "Only if the electronic record is duly produced in terms of Section 65B of the Evidence Act, the question would arise as to the genuineness thereof and in that situation, resort can be made to Section 45A" (para 16). Why it matters now: s.45A is s.39(2) and s.65B is s.63, so on a reading of the text the same sequence applies. The certificate question is covered on the Section 65A–65B page.

C. Kamalakkannan v. State of Tamil Nadu, [2025] 3 S.C.R. 629 (2025 INSC 309), decided 3 March 2025. Sandeep Mehta J. delivered the judgment of a two-judge bench (with Vikram Nath J.). The prosecution's highest case was that a postal cover bore the appellant's handwriting, a fact it sought to prove through a handwriting expert (para 11). Following Murari Lal (para 12), the Court held that because the original cover was never exhibited, it "was never proved as per law" and the expert's report was "rendered redundant" (para 13). The appellant was acquitted (paras 15–17). Why it matters now: decided under IEA s.45 (a 1996 prosecution), it holds that an opinion cannot stand in for proof of the document it concerns.

Which law applies to your case

BSA s.170(2) provides that any application, trial, inquiry, investigation, proceeding or appeal pending immediately before the Adhiniyam came into force is dealt with under the IEA "as if this Adhiniyam had not come into force". A case pending on that date applies IEA ss.45 and 45A. On a reading of s.170(2), a proceeding begun later applies BSA s.39. For s.39(2) nothing turns on it. For s.39(1) the only difference is the words "or any other field". For the full analysis see which law applies to an offence before 1 July 2024.

Frequently asked questions

What is the BSA equivalent of Section 45 of the Evidence Act? Section 39(1) of the Bharatiya Sakshya Adhiniyam, 2023 replaces Section 45 of the Indian Evidence Act, 1872, and Section 39(2) replaces Section 45A. The three illustrations (poison, unsoundness of mind, handwriting comparison) are unchanged. Sections 46 and 51 of the old Act, on facts bearing upon expert opinions and the grounds of opinion, become Sections 40 and 45 BSA without change.

What does "or any other field" add in Section 39(1) BSA? Section 45 IEA covered foreign law, science or art, and identity of handwriting or finger impressions. Section 39(1) BSA adds "or any other field" after "science or art", both where it describes the point on which the Court forms an opinion and where it describes the persons specially skilled. The witness must still be "specially skilled" in that field; how widely courts will read the new words is not settled by any Supreme Court judgment read for this page.

Is the Examiner of Electronic Evidence a new kind of expert under the BSA? No. Section 45A IEA, inserted by Act 10 of 2009 (w.e.f. 27 October 2009), already made the opinion of the Examiner of Electronic Evidence referred to in Section 79A of the IT Act a relevant fact, and its Explanation already said such an Examiner shall be an expert. Section 39(2) BSA repeats this, changing "this section" to "this sub-section". Under Section 79A the Central Government specifies an Examiner by notification in the Official Gazette.

Is a court bound to accept an expert's opinion under Section 39? No. Section 39 makes the opinion a relevant fact, not proof. In State of H.P. v. Jai Lal (1999 INSC 393) the Supreme Court said an expert is not a witness of fact and that his evidence is advisory, and in Ramesh Chandra Agrawal v. Regency Hospital (2009 INSC 1131, para 15) it repeated that the expert's credibility depends on the reasons and data given for the conclusion.

Must a handwriting expert's opinion be corroborated before a court acts on it? Not as a rule of law. In Murari Lal v. State of M.P., [1980] 2 S.C.R. 249, the Supreme Court held that there is no rule of law or crystallised rule of prudence requiring substantial corroboration, but that the approach should be cautious and the reasons probed. It also held that Section 73 IEA (now Section 72 BSA) lets the Court compare disputed and admitted writings itself. C. Kamalakkannan (2025 INSC 309, para 12) followed Murari Lal.

Can an expert report be used without calling the expert as a witness? As a general rule, no: in Jai Lal the Supreme Court said an expert's report does not go into evidence automatically and the expert must face cross-examination. In criminal proceedings, Section 329 BNSS (formerly Section 293 CrPC) lets reports of listed Government scientific experts, such as a Chemical Examiner or a Forensic Science Laboratory director, be used as evidence, with power to summon the expert. The second proviso to Section 330(1) BNSS says no expert shall be called unless the report is disputed by a party.

Does a Section 39(2) expert opinion replace the Section 63 certificate for electronic records? No, they do different jobs. Section 63(4) BSA requires a certificate in the Schedule form, signed by the person in charge and an expert, to be submitted with the electronic record at each instance it is submitted for admission. In Anvar P.V. v. P.K. Basheer (2014 INSC 645, para 16) the Supreme Court said that only once an electronic record is duly produced under Section 65B does the question of its genuineness arise, and then resort can be had to Section 45A.

Sources

Acts and sections read (BSA and BNSS from the Gazette; Indian Evidence Act and CrPC from the official texts; IT Act from the Bare Act library): BSA ss.1(3), 2(1)(j)–(k), 39, 40, 41, 45, 63(4), 72, 170 and the Schedule; IEA ss.45, 45A, 46, 47A, 51; IT Act s.79A; BNSS ss.329, 330; CrPC ss.293, 294.

Judgments read (full text, Veritect Supreme Court corpus): Murari Lal v. State of Madhya Pradesh (1980_2_249_259_EN.md); State of Himachal Pradesh v. Jai Lal (S_1999_2_318_327_EN.md); Ramesh Chandra Agrawal v. Regency Hospital Ltd. (2009_14_424_440_EN.md); Anvar P.V. v. P.K. Basheer (2014_11_399_427_EN.md); C. Kamalakkannan v. State of Tamil Nadu (2025_3_629_637_EN.md).

This page explains the statutory text and the judgments cited as they stand. It is not legal advice; for a specific case, consult an advocate.

Section 45 Evidence Act vs Section 39 BSA — Expert Opinion