In a Moroccan village, there is a mosque imam who consumes hashish. The question is regarding the ruling on praying behind him.

All praise is due to Allah. Drug abuse is a major sin, and the Imam must be advised to repent. However, praying behind him is valid because praying behind a transgressor is permissible, just as the Companions prayed behind Al-Hajjaj. Nevertheless, it is disliked by scholarly consensus, and it is preferable to put someone else forward if possible, provided that he fulfills the conditions and pillars of prayer correctly.