Mr Bello Abubakar challenged Muslim scholars two weeks ago
Nigeria's Islamic authority has told the man who has 86 wives to choose only four and repent within three days or else he will be sentenced to death.
The Jamatu Nasril Islam (JNI) passed their verdict on Mohammed Bello Abubakar, 84, according to Sharia law.
This comes two weeks after the Nigerian press and the BBC reported on the case.
Talking to the media then, Mr Abubakar challenged Muslim scholars, saying there is no punishment stated in the Koran for having more than four wives.
However, Mr Abubakar advised other men not to follow his example and marry 86 women.
The former teacher and Muslim preacher lives in Niger State with his wives and at least 170 children, and says he is able to cope only with the help of God.
"A man with 10 wives would collapse and die, but my own power is given by Allah. That is why I have been able to control 86 of them," he told the BBC.
Most Muslim scholars agree that a man is allowed to have four wives, as long as he can treat them equally.
But Mr Bello Abubakar told the BBC: "To my understanding the Koran does not place a limit and it is up to what your own power, your own endowment and ability allows.
"God did not say what the punishment should be for a man who has more than four wives, but he was specific about the punishment for fornication and adultery."
Niger is one of the Muslim majority states to have reintroduced Sharia punishments since 2000.
Several people have been sentenced to death for adultery by Sharia courts but none of these sentences have been carried out.