• Giving up claim to presidency?
• 'My husband did not renounce his mandate'
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ABUJA, Nigeria (CNN) -- Nigerian officials said on Friday the release of celebrated political detainee Moshood Abiola was imminent because he had agreed to give up his claim to the presidency, an assertion Abiola's backers rejected.

U.N. Secretary-General Kofi Annan announced Thursday that Nigeria will free all of its remaining political prisoners, including Abiola, 60. He gave no timetable, just saying "the government will make an announcement at the appropriate time."

Annan, after four days of frantic diplomacy involving new military ruler Gen. Abdulsalam Abubakar, said Abiola had realized it would be "naive" to expect to leave detention and immediately become president.

Abiola was locked away in 1994 for proclaiming himself president on the basis of a 1993 election he is widely believed to have won.

The election has been at the heart of political confusion in Nigeria, Africa's most populous nation, since they were annulled by Gen. Sani Abacha, the Nigerian dictator who died last month.

Kofi Annan

Giving up claim to presidency?

Government officials said that it was only after meeting Annan and Emeka Anyaoku, the secretary-general of the commonwealth of former British colonies, that Abiola had considered giving up his claim.

"Chief Abiola has been asked to prepare his bags and tidy up his things," one senior government official said in Abuja after the ruling military council met with Abiola's case at the top of the agenda.

"We cannot give an exact time for his release but it is fair to say it will be very soon and there will be an official announcement," the official said.

One of Abiola's wives, Doyin Abiola, told Lagos Radio late Thursday she had "reason to believe" he would probably be freed in the near future.

'My husband did not renounce his mandate'

But another of his wives, Dupe Onitri-Abiola, said in a statement that it was "unreasonable" of Annan to imply that her husband had given up his claim and described such reports as propaganda by Abubakar's government.

"My husband did not renounce his mandate... I would like to appeal to all supporters of my husband and the people of Nigeria to remain steadfast. Their devotion, dedication and loyalty must not be weakened. The struggle continues," she said.

Her skepticism was echoed by one of Abiola's followers. "I don't see where in the statement where Kofi Annan stated categorically that Abiola had renounced his mandate and he certainly couldn't have done it without consulting his supporters," said Abraham Adesanya, leader of the opposition National Democratic Coalition (NADECO).

"We do not believe he said so and even if he said so while still in captivity that agreement cannot be binding because it is made under duress," Adesanya added.

"It is not binding on NADECO or the 14 million people who voted for him at that election," he said. "We therefore appeal to all Nigerians to be calm until they hear directly from Abiola."

There are believed to be between 250 and 280 political prisoners still held in Nigerian prisons, though thousands were arrested at various times during Abacha's rule. Abubakar has repeatedly signaled that he intends to break from his predecessor's policies.

The United States said it would send a high-level mission over the weekend to meet Abubakar and encourage him in his promise to restore democracy to the West African state, which has been ruled by soldiers for all but 10 years since independence from Britain in 1960.

The Associated Press and Reuters contributed to this report.