A second Pentonville prisoner was yesterday charged with murder after the fatal stabbing of fellow inmate Jamal Mahmoud last month.

Robert Butler, 30, was the third person to be arrested after the killing on October 18. Basana Kimbembi, 34, of no fixed abode, was charged three days after Mr Mahmoud’s death, while a second man has been released from police custody without charge and returned to the Caledonian Road prison.

Kimbembi will appear at the Old Bailey in January.

Mr Mahmoud, 21, was jailed for six and a half years in July after being convicted of hiding a loaded Skorpion machine gun and ammunition in a garden in Enfield the previous July. He was already serving five-and-a-half years in prison for a separate robbery.

He had recently become a father.

A manhunt is under way after two men, including attempted murderer James Whitlock, escaped from the jail after reportedly stowing pillows in their beds and cutting through their cell bars.

Additional reporting by PA