A Ma'mum who knows that the Imam is ritually impure before offering Salah

Q 2: What is the ruling on whoever discerned the ritual impurity of the Imam (the one who leads congregational Prayer) behind whom he offers Salah (Prayer)? What should he do?

A: If a Ma'mum (a person being led by an Imam in Prayer) knew before offering Salah (Prayer) that the Imam was ritually impure, it is not permissible (Part No. 6; Page No. 300) for him to offer Salah behind him. The same applies if he knew of that matter while offering Salah and the Imam did not make someone else succeed him to lead people in the remainder of the Salah, as Taharah (ritual purification) is a prerequisite for the validity of Salah. Thus, he should repeat Salah if he offered it behind the said Imam. However, if the Ma'mum (a person being led by an Imam in Prayer) did not know of that matter until Salah was concluded, his Salah is valid and there is no need for him to repeat it.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.