What is the ruling on an imam who prayed with the congregation while in a state of major ritual impurity, not knowing that he was in a state of major ritual impurity?

The questioner : The honorable Shaykh, a man who is the imam of a mosque and a جامع (gathering place) for his wife, and he led the people in the Fajr, Zuhr, and 'Asr prayers, and he did not remember until Maghrib. How is this?

The Shaykh : He says: This is an imam who prayed with the congregation while in a state of major ritual impurity; he prayed Fajr, Zuhr, and 'Asr and did not know until after that? We say: He must perform the full ritual bath and repeat his prayer. As for the congregation, they owe nothing.