A senior judge has highlighted the “disturbing” smuggling trade in Britain’s prisons as he jailed an inmate for 12 years for a vicious knife attack at HMP Pentonville during a fight which left a second man dead.

Basana Kimbembi, 35, formerly of Barking, was found not guilty of murdering 21-year-old Jamal Mahmoud in October last year but was convicted of wounding his friend Mohammed Ali, 22, following a three-month trial at the Old Bailey.

The violent confrontation on G Wing was over ownership of a football-sized package of phones and drugs brought into the crisis-hit north London jail on sheets.

Mahmoud, aka Kaos, leader of a Somali faction and the Get Money Gang, in Enfield, was a “major player” in the contraband trade and had demanded a share of Kimbembi’s consignment, jurors had heard.

During the fight, Kimbembi repeatedly stabbed Ali in the chest, leg and buttocks with a Rambo-style knife.

Jailing Kimbembi today, Judge Richard Marks QC said: “As emerged during the course of the trial, certainly on G Wing where these events occurred, the picture that emerged was, to say the least, highly disturbing in that it appeared that such items were in abundant supply, coming into the prison by a number of different ways.

“It is a statement of the obvious that this is bound to lead to a large catalogue of very serious problems, not the least of these is the fact that these items represent very valuable currency to those importing them into the prison which can in turn lead to major conflict if rival factions or individuals are involved in such activity, as was in fact the case at the time of these events.”

Kimbembi has previous convictions for 15 offences, including a cash-in-transit robbery, and had been fighting deportation to the Congo at the time of the attacks.

Giving evidence, Kimbembi denied stabbing Mahmoud in the stomach and claimed he knifed Ali with his own blade because he was “trying to stab me”.

Judge Marks said he had no doubt Kimbembi was armed with the large hunting knife which was later recovered in Ali’s cell with his blood on it.

Two other inmates, Joshua Ratner, 27, and Robert Butler, 31, were cleared over the attacks.