The governor of Armley Jail admitted drugs had been smuggled into the prison and said eight prisoners had been found in possession of cannabis.
The allegations followed revelations from an ex-con who told the Yorkshire Evening Post the jail was “like a powder keg” and was “ready to explode”, due to overcrowding and understaffing.
It was claimed the prison, which was designed to hold 591, had a population of 1,300.
Governor William Martin said at the time: “I think eight prisoners have been caught in possession of cannabis after an incident in July. I made it pretty hot for them and it became unfashionable to be caught with it.
He added that given what he described as “humane and liberal” visiting arrangements between prisoners and their loved ones, family and friends, it was virtually impossible to prevent contraband being smuggled into the jail.
He said drugs were smuggled in during visits and also in food parcels, which prisoners were allowed.
In addition to cannabis being found, it was also alleged LSD had been smuggled in.