What is the ruling on the the call to prayer (adhan) made by a disbeliever? And should one repeat after him?

The Adhan (call to prayer) made by a disbeliever is not valid, because among the conditions for the validity of the Adhan is that the Muezzin (caller to prayer) must be a Muslim. This is because a disbeliever is not among those obligated to perform acts of worship, nor does he believe in prayer. His Adhan would be a mockery and legally null and void, thus it is not permissible to recount it.