I pray in a mosque called Alkhalil mosque in Adelaide Australia. This mosque is very big and new, build by Palestinian Muslim. I personally do not know the person who built the mosque but I heard that he trades with cigarettes and deals with interest (Riba). Some Muslims even accuses him of building this mosque with money of (Riba). I know he lives close to the mosque, but I have never seen him praying with us. Should I pray in such a mosque or not? Please note this is the only mosque close to me.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Prayer in a mosque that was built from forbidden earnings is lawful and the sin of dealing in what is forbidden applies totally to the person who built the mosque and not the people who pray in it.

Allah knows best.