Victim Jamal Mahmoud was 21.

The jury have found Basana Kimbembi, 35, Robert Butler, 31, and Joshua Ratner, 27, not guilty of murder. But they convicted Kimbembi of wounding Mr Mahmoud’s friend Mohammed Ali with intent to cause grievous bodily harm.

Jamal Mahmoud, 21, was killed in October last year in a gang-related attack.

Jurors were told that the victim, nicknamed Kaos, was leader of a “Somali” gang which clashed with Kimbembi over the delivery of a package of drugs and phones into Pentonville Prison.

It was alleged that the defendants armed themselves to confront Mahmoud on the top level of Pentonville over G Wing, where the CCTV had been deactivated years ago.

During the fight, Mahmoud was stabbed in the chest and his friend, Ali, was wounded by Kimbembi who had a large combat knife, jurors were told.

Kimbembi and Butler both denied delivering the fatal wound to Mahmoud and said their co-accused, Ratner, was not involved.

Judge Richard Marks QC adjourned Kimbembi’s sentencing until Monday.