What is the ruling if an Imam leads a prayer, and two witnesses testify that the Imam broke ablution, while the Imam and the rest of the congregation deny it?
Chapter on Praying with Impurity and Other Matters
Al-Mughni
Book of Prayer
Primary text
The Imam and all the followers must repeat the prayer (repetition/re-qada). This is because the testimony of two witnesses establishing a fact (breaking ablution) takes precedence over the denial by the Imam and others, as there is a possibility the witnesses possess knowledge unknown to the Imam and the rest of the congregation.
Supporting text
It is possible that the obligation to repeat the prayer is restricted only to those who gained knowledge of the Imam's impurity, contrary to the explicit statement that all followers must repeat the prayer upon the documented position.