Last Updated: August 22 2026
In Ontario civil litigation, when can a court draw an adverse inference if a party fails to produce documents or testify?
Lo Greco Law can help you understand how adverse inference (also called a negative inference) works when a party does not produce relevant evidence or testimony that was reasonably expected from them, because courts may presume the evidence was avoided since it was unfavourable to that party and the inference is discretionary rather than automatic; cases like Tiwari v. Chevalier, 2022 ONSC 3071 and Lane v. Kock, 2015 ONSC 1972 note adverse inferences may be drawn from failure to produce relevant documents or call material evidence, while Parris v. Laidley, 2012 ONCA 755 explains the court considers the specific circumstances including whether there is a legitimate explanation, whether the evidence was within the party’s exclusive control, and whether the witness would provide key facts; with 30+ year experienced lawyer services and LSO tribunal representation, Lo Greco Law helps Ontario clients prepare evidence strategy, respond to requests for production, and address spoliation or gaps in proof, so you can reduce delays and protect your position, call (416) 488-4110 to discuss your matter today.
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Understanding the Principle of Adverse Inference as an Evidentiary Rule Arising from Failure to Produce Evidence
An adverse inference, which may sometimes also be called a negative inference, may occur a litigant fails to provide evidence or fails to provide testimony that was reasonably expected to come from the litigant. Where the litigant fails to provide the expected evidence or the expected testimony, the court may presume that the litigant avoided the evidence or testimony because such was unfavourable.
Note: Please contact Lo Greco Law by phone at: (416) 488-4110 to discuss any specific questions that you may have.
The Law
An adverse inference presumption arises from the expectation that where a litigant is in possession of evidence or control of a witness, the litigant would provide the evidence or present the witness unless the evidence or witness is harmful to the case of the litigant. The legal doctrine was provided within the cases of, among others, Tiwari v. Chevalier, 2022 ONSC 3071, and Lane v. Kock, 2015 ONSC 1972, which respectively stated:
[28] Adverse inferences may be drawn from a party’s failure to produce relevant documents they were required to produce or should have produced. (Sarzynick v. Skwarchuk, 2021 BCSC 443, at para. 190.)
[3] The effect of the failure of a party to testify or to call a material witness or other evidence, is summarized as follows in Sydney N. Lederman, Alan W. Bryant & Michelle K. Fuerst, The Law of Evidence in Canada, 4th ed. (Markham: LexisNexis Canada, 2014) at p. 386:
In civil cases, an unfavourable inference can be drawn when, in the absence of an explanation, a party litigant does not testify, or fails to provide affidavit evidence on an application, or fails to call a witness who would have knowledge of the facts and would be assumed to be willing to assist that party. In the same vein, an adverse inference may be drawn against a party who does not call a material witness over whom he or she has exclusive control and does not explain it away. Such failure amounts to an implied admission that the evidence of the absent witness would be contrary to the party's case, or at least would not support it.
The adverse inference principle is discretionary and a judge is without a requirement to apply the principle where circumstances warrant. The basis for discretionary application of the adverse inference principle was explained by the Court of Appeal in Parris v. Laidley, 2012 ONCA 755, whereas it was stated:
[2] Drawing adverse inferences from failure to produce evidence is discretionary. The inference should not be drawn unless it is warranted in all the circumstances. What is required is a case-specific inquiry into the circumstances including, but not only, whether there was a legitimate explanation for failing to call the witness, whether the witness was within the exclusive control of the party against whom the adverse inference is sought to be drawn, or equally available to both parties, and whether the witness has key evidence to provide or is the best person to provide the evidence in issue.
Summary Comment
The principle of adverse inference is the legal version of saying, if you got it, then flaunt it; and, if a party fails to do so, the court may presume that a party who fails to use evidence does so because the evidence would be unfavourable.
