Last Updated: August 21 2026
In an Ontario civil case, when can a court draw an adverse inference because a party failed to produce evidence or call a witness?
In Ontario civil litigation, an adverse (negative) inference may be drawn when a party fails to produce relevant documents they were required to produce (or should have produced), or fails to testify or to call a material witness who would be expected to provide helpful evidence, particularly where the witness or documents were within that party’s possession, control, or exclusive control and there is no legitimate explanation for the omission. The court’s decision is discretionary and case-specific, so the judge will consider factors such as whether the missing evidence or witness was available to both parties, whether there was a reasonable excuse, and whether the witness had key knowledge or was the best person to provide it. For practical guidance on how these principles can affect your dispute and what evidence you should produce (or address), SFG Paralegal Services LLP can help you prepare an evidence strategy for small claims or civil matters across Ontario, including next steps before a motion or trial; call (888) 398-0121.
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Understanding the Principle of Adverse Inference as an Evidentiary Rule Arising from Failure to Produce Evidence
An adverse inference may arise where a party fails to testify, or where a party fails to lead evidence that is in control of the evidence, and from such a failure the court may thereby presume that the reason for the absence of the evidence or the absence of testimony is that such would negatively affect the party who fails to provide the testimony or the evidence.
Note: Please contact SFG Paralegal Services LLP by phone at: (888) 398-0121 to discuss any specific questions that you may have.
The Law
The adverse inference presumption is based upon the expectation that if a party has control over evidence, the party would present the evidence unless the evidence was unfavourable to the party. The principle was well explained within the case of Tiwari v. Chevalier, 2022 ONSC 3071, as well as the case of Lane v. Kock, 2015 ONSC 1972, wherein each it was respectively said:
[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 choice to apply an adverse inference is discretion as was explained within the Court of Appeal case of Parris v. Laidley, 2012 ONCA 755, wherein it was said:
[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.
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