A Christian leader in Nigeria says security agents have ordered him to apologise to the president after the two men had a public row.
Thousands of Christians have fled clashes in Kano
Reverend Yakubu Pam told the BBC that he was questioned for several hours.
President Obasanjo described Reverend Yakubu as an "idiot" when he questioned Mr Obasanjo's commitment to ending ethnic and religious violence.
Clashes between Christians and Muslims have killed hundreds of people this month in central and northern Nigeria.
Reverend Pam, head of the Plateau State branch of the Christian Association of Nigeria (Can), said he was consulting with his colleagues over whether to apologise.
On Thursday, he asked Mr Obasanjo in front of reporters why the president had not come to the area two months ago when dozens of Christians were killed in a Muslim raid.
The president replied: "What role have you played to bring about peace as Can chairman in Plateau State? Can, my foot! What kind of Can chairman are you? Did your own Christianity teach you about revenge?
"You are an idiot. A total idiot. And I have no apologies for that," said Mr Obasanjo, a born-again Christian.
He also responded sharply when Abdulazeez Yusuf, secretary general of the Muslim association Jamu'atu Nasril Islami, asked whether Mr Obasanjo was serious about bringing peace to Nigeria.
Mr Obasanjo later visited the town of Yelwa, scene of last week's massacre by Christian militants and a relief camp where 27,000
people had fled.
There have been no reports of further clashes in the mainly Muslim city of Kano, where Muslims youths attacked Christians and others from outside the state with knives and machetes.
Some 22,000 people sought shelter at police stations after their houses were burnt down. At least 30 deaths have been confirmed but a Red Cross official says that many more may have died.
Obasanjo is accused of not doing enough to stop communal clashes
"I saw them put an old tyre on his neck and set him ablaze," said a 30-year-old Christian, Barry Owoyemi, of a dead Christian neighbour.
Armed police and soldiers are patrolling the city's streets and an overnight curfew remains in place.
They also turned out in the commercial capital, Lagos, and northern cities in an attempt to keep the peace.
Some 10,000 people have been killed in ethnic, religious and communal clashes in Nigeria since Mr Obasanjo was elected in 1999, ending a long period of military rule.
Nigeria is roughly evenly divided between Christians, mostly in the south, and Muslims, largely in the north.