Kabiru Sokoto, member of Boko Haram
Kabiru Sokoto, member of Boko Haram Reuters

An armed prison breakout by members of Nigeria's Islamist terror group, Boko Haram, has freed 118 inmates, reports have claimed.

The storming of the prison followed reports of a "deep throat" inside Boko Haram, who alleged that senior figures in the country's establishment were bankrolling the group.

Twenty Boko Haram members reportedly armed with bombs and guns attacked the prison in Koton Karfe, in Nigeria's central Kogi State, and killed a guard.

"They opened fire on one of the security men at the entrance of the prison and killed him on the spot. The main gate of the prison was bombed by the Boko Haram members," said witness Mariamu Bello.

The latest incident follows revelations that Kabiru Sokoto, a member of the sect, has identified its financial backers.

"The man is co-operating well with us," an unnamed source inside the security forces told the Lagos-based Daily Champion.

Sokoto is a suspect in the deadly Christmas bombing of a church near the capital Abuja, which killed 43 people and left dozens injured.

Boko Haram had previously attacked a number of other prisons to free members and also managed to help Sokoto escape police custody, although he has since been rearrested.

He allegedly admitted that security forces are getting closer to the inner circle of the Islamist radical sect.