Prayer: Must prayers be repeated if the Friday Imam is later found unjust?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Must prayers be repeated if the Friday Imam is later found unjust?

English:

Question #618:

Is it necessary to repeat the prayers one has prayed behind a Friday prayer Imam whose justice is questionable or, Allah forbid, if it is established that the imam is not ‘ādil?

Answer #618:

If doubt about the Imam’s justice or certainty about the lack of justice is acquired after completing the prayer, then it is not obligatory to repeat the prayers and they are considered correct.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer