An Islamic court in Bauchi state has put on trial 11 Muslim men accused of being homosexuals in violation of their religion, a religious leader has told the BBC.
A 12th person arrested – a Christian – would be tried under secular law, a BBC reporter says.
Under Islamic law, a person can be sentenced to death by stoning if convicted of homosexuality.
It is also illegal to have gay sex in Nigeria, according to its secular laws.
Jibrin Danlami Hassan, the commissioner of Bauchi state’s Sharia Commission, said the alleged homosexuals were arrested by residents of Bauchi city.
They were handed to the Islamic police force, which interrogated them, he said.
“They accept that they are doing that dirty game,” Mr Hassan said.
Ms Aken’Ova, a rights activist with the Nigeria-based International Centre for Reproductive Health and Sexual Rights, said some of those arrested had been beaten up and tortured, but Mr Hassan denied this.
The BBC’s Ishaq Khalid in Bauchi says the Sharia Commission confirmed to him that a Christian had been arrested with the 11 Muslims, and would be tried in a “conventional court”.
The Muslims could be sentenced to death by stoning if they are convicted, but the court would decide, Mr Hassan said.
Several stoning sentences have been handed down by Sharia courts in northern Nigeria since 1999; however, none have so far been carried out.
The UK, US and UN human rights chief, Navi Pillay, have condemned Nigeria’s Same-Sex Marriage Prohibition Act as discriminatory and draconian.
Mr Hassan said told the BBC he was “happy” that Mr Jonathan had signed it into law, despite threats by Western powers to cut aid to Nigeria.
“The threat they are doing cannot make us change our religion,” he said.
Earlier this month, President Goodluck Jonathan signed a National Assembly bill into Law, which tightens laws against homosexuals, banning same-sex marriages, gay groups and display of same-sex public affection.
The new legislation applies across Nigeria, affecting all citizens.