A member of Islamist group Boko Haram has confirmed one of the group's high-ranking members was arrested, but refuted reports that the detained person was its spokesman.
In a phone conference with journalists in the northeastern city of Maiduguri late Thursday, the man said Boko Haram's head of "public enlightenment" Abu Dardaa was arrested and not spokesman Abul Qaqa.
The man speaking on the phone claimed to be Abul Qaqa himself, but his voice sounded different from previous such conferences in which the purported spokesman has claimed responsibility for scores of deadly attacks.
There has also long been speculation over whether those going by the aliases Abul Qaqa and Abu Dardaa are the same person.
"We want to react on what security agents said regarding the arrest of one of our members," the man said.
"The person that was arrested was Abu Dardaa and not Abul Qaqa. I am Abul Qaqa ... Abu Dardaa is the head of the 'Lajina', the department of public enlightenment, and not the spokesman."
A senior secret police official, speaking on condition of anonymity, said it appeared the person who issued the comments was indeed connected to Boko Haram, but he dismissed the statements as propaganda.
"It is no surprise they are making this ridiculous claim," the source said. "Abul Qaqa is part of the 11-member Shura council, the sect's decision-making body, and his arrest is a serious setback to the sect."
Security sources said Wednesday that a suspect believed to be the person who goes by the alias Abul Qaqa had been arrested. Authorities have not officially confirmed his detention or his identity.
The man claiming to speak on behalf of Boko Haram alleged that Dardaa was arrested when he was sent to the northern city of Kaduna for negotiations with government officials.
"The arrest of Abu Dardaa is an outright deception and betrayal by the Nigerian government and security agents," he said. "They proclaim dialogue but are doing the opposite."
With authorities unable to stop attacks blamed on Boko Haram, there have been growing calls for dialogue to bring an end to the violence.
"We want to reiterate that no amount of threat, arrest and intimidation will deter us from our course," the purported Boko Haram spokesman said. "We are not afraid of death and we are ever ready to die."
Boko Haram's deadliest attack yet occurred on January 20, when coordinated bombings and shootings killed at least 185 people in Nigeria's second-largest city of Kano.
The group also claimed responsibility for the August suicide bombing of UN headquarters in Abuja that left at least 25 people dead.
It has in the past claimed to be fighting for an Islamic state in Nigeria's mainly Muslim north, but its demands have repeatedly shifted.