A Nigerian journalist with links to the jihadist militant group Boko Haram has claimed that only 15 out of the 112 missing Chibok girls are still alive.
Boko Haram raided a government school on the night of 14-15 April 2014, kidnapping 276 female students.
Over the next few months, more than 50 managed to escape from captivity but the others remained in the militants’ detention.
Journalist Ahmad Salkida said he had negotiated for the girls’ release on behalf of the government, but several opportunities to have them freed had been missed.
BBC news agency reports Salkida to have said the administration of former President Goodluck Jonathan had asked him to negotiate for the release of the Chibok schoolgirls two weeks after they were abducted.
He said he had arranged for a prisoner swap on five occasions, but delays from the then government led to a breakdown in negotiations.
The Chibok girls’ continued stay in captivity has elicited worldwide responses as the international community seeks to have the girls re-united with their parents.
On Saturday, the parents marked the fourth anniversary of the kidnappings by marshing with thousands of others to the school in the north-eastern Borno state, where Chibok lies.
Boko Haram has been a thorn in Nigerian governments for more than a decade, as it wages war seeking to instil a strict jihadist system of governance.
The war has killed thousands and displaced millions from their homes.