Bharatiya Sakshya Adhiniyam, 2023 · Chapter II: Relevancy of Facts · Opinions of third persons when relevant
Section 39: Opinions of experts
In plain words
When the court must form an opinion on foreign law, science, art or any other field, or on identity of handwriting or finger impressions, the opinions of specially skilled persons (experts) are relevant.
- For information stored or transmitted in a computer resource or electronic form, the opinion of the Examiner of Electronic Evidence under section 79A of the Information Technology Act, 2000 is relevant, and that Examiner counts as an expert.
Example: Whether a death was caused by poison: experts' opinions on the symptoms that poison produces are relevant.
A simplified explanation, prepared with AI assistance from the official text below and checked automatically against it for numbers and cross-references. The official text is the law and prevails over this summary. Not legal advice.
Read the in-depth explanation, with key Supreme Court rulings ↓
Official text
(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.
Illustrations
(a) The question is, whether the death of A was caused by poison. The opinions of experts as to the symptoms produced by the poison by which A is supposed to have died, are relevant.
(b) The question is, whether A, at the time of doing a certain act, was, by reason of unsoundness of mind, incapable of knowing the nature of the act, or that he was doing what was either wrong or contrary to law. The opinions of experts upon the question whether the symptoms exhibited by A commonly show unsoundness of mind, and whether such unsoundness of mind usually renders persons incapable of knowing the nature of the acts which they do, or of knowing that what they do is either wrong or contrary to law, are relevant.
(c) The question is, whether a certain document was written by A. Another document is produced which is proved or admitted to have been written by A. The opinions of experts on the question whether the two documents were written by the same person or by different persons, are relevant.
(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 (21 of 2000), is a relevant fact.
Explanation.—For the purposes of this sub-section, an Examiner of Electronic Evidence shall be an expert.
Corresponding sections were matched by comparing the wording of both official texts, and for the IPC and BNS, also against a published correspondence table. Wording, punishments and structure often changed, so read both sections before relying on the match.
Source: India Code (indiacode.gov.in), the consolidated text published by the Legislative Department, Government of India. Text as updated on India Code on 25 August 2026. Words in square brackets [ ] were inserted or substituted by later amending Acts, and *** marks words omitted by an amendment. The amendment footnotes are not reproduced here. Official text on India Code.
Understanding this section
Section 39 carries forward section 45 of the Indian Evidence Act: opinions of experts on foreign law, science, art, handwriting, finger impressions, and now expressly any other field, are relevant. As before, the court is not bound by them.
Expert evidence in practice
The expert must be shown to have special skill. The court examines the reasons for the opinion, weighs it with the rest of the evidence, and decides. There is no rule of law requiring corroboration, but caution is needed in imperfect sciences such as handwriting comparison.
Electronic evidence experts
Sub-section (2) recognises the opinion of the Examiner of Electronic Evidence under the Information Technology Act as relevant when the court must form an opinion on information in an electronic record.
Key Supreme Court rulings
Gastrade International v. Commissioner of Customs, Kandla 2025 INSC 411
Decided under the Evidence Act. An expert opinion assists the court; "Such report is not binding upon the court."
C. Kamalakkannan v. State of Tamil Nadu 2025 INSC 309
No rule of law requires a handwriting expert's opinion to be corroborated before it is acted on, though caution and scrutiny of reasons are needed.
Common mistakes
- Treating expert opinion as conclusive.
Read with: Section 45 Evidence Act
Prepared with AI assistance as a study aid. Every ruling listed was checked against the Supreme Court's own judgments on this site, and quoted words appear in those judgments; linked names open the full judgment. Read the judgments themselves before relying on them. Not legal advice.
Supreme Court judgments citing the section 39
No Supreme Court judgment in our database cites this section yet.