Fourteen prison officers were suspended today following corruption allegations.
A Prison Service spokeswoman said the officers were suspended by the Governor of Pentonville prison in north London this morning.
The jail will "briefly reduce" its maximum number of inmates - at a time of record prison numbers in England and Wales - as a result of the move, she added.
She went on: "This morning the governor of HMP Pentonville has taken the decision to suspend 14 officers following allegations of corrupt behaviour.
"All those suspended will be subject to investigations led by senior governors from other prisons in the London area.
"If any alleged or otherwise suspected criminal activity is uncovered during the investigations relevant information will be passed to the police."
Prison Service director general Phil Wheatley said: "I will not tolerate staff corruption of any sort by any member of the Prison Service.
"Allegations of corruption will be investigated thoroughly and where evidence is found to support those allegations the appropriate disciplinary action will be taken."