Judicial principles and studies
Complementary Oath
A complementary oath is an oath the court directs on its own initiative to remedy incomplete evidence in prosecution or defense; it serves to supplement the court’s conviction but cannot stand as the sole proof.
Updated: 10 September 2026
Prepared and reviewed by: Ashraf Al-Khawaja
Subject
A complementary oath is a measure the court may direct on its own initiative to one party when the presented evidence—on either prosecution or defense side—is incomplete. Its function is to fill an evidentiary gap and help the judge form a conviction about disputed facts.
Summary
The complementary oath operates as a supplemental aid to the court’s conviction and is not an appeal to the party’s conscience. It cannot serve as the sole piece of evidence, and it must not be used when the case lacks any evidence whatsoever. The oath is typically directed to the party whose proof is incomplete so they can complete their evidence and enable the court to decide. This content is a general educational summary and is not judicial text or legal advice.
Practical significance
Practically, the complementary oath is a limited tool to address evidentiary deficiencies; it cannot replace substantive proof. Its use requires confirming that some evidence already exists and avoiding reliance on the oath as the only basis for a decision.
Sources and references
Verify the official text and latest amendments before relying on this material professionally.