Brady was able to mix with young boys from a borstal for five years while he was in Wormwood Scrubs, according to files released by the Home Office.
The serial murderer and his girlfriend Myra Hindley tortured and sexually assaulted five children as they buried their bodies on Saddleworth Moor, near Manchester, in 1963 and 1964.
He eventually found his way to London lockup Wormwood Scrubs in 1974 – where boys from Feltham Borstal would attend if they were suffering mental health problems.
Manipulative and callous Brady was allowed to stay on the hospital ward after staging a hunger strike – being held on the Mental Observation Landing, known as G2.
It is here that Brady began to associate with the youngsters as young as 15 and is alleged to have had sex with one, reports the BBC.
“Brady wouldn’t just have had free run of the passageway outside the rooms”
Prison reports detail that medics noticed he was taking an “unusual interest” in “adolescents” in 1976.
“His influence in such a situation is certainly not a wholesome one,” a report dated September 2 reads.
Staff had to move the young boys off the landing to keep them away from Brady.
Complaints were made – but Brady stayed on the landing and his privileges increased, being given duties such as cleaning the toilets and showers.
Brady was also allowed to sit and watch television with other patients including the boys.
For five years this continued until 1981, in which one boy claimed that Brady had sex with him.
The Moors Murderer was promptly moved back to Pankhurst on the Isle of Wight in 1982.
It is believed Brady managed to get his cushy treatment and access to the boys as he was “manipulative” and “arrogant”.
Peter Meakings, assistant governor of Wormwood Scrubs at the time, said: “As the landing cleaner, Brady wouldn’t just have had free run of the passageway outside the rooms, where there were officers supervising, he would also have had access to the toilets.”
The boy told the medical officer about his experience with Brady, with a letter to the governor described him as in a “very agitated state”.
He was terrified about what Brady would do if he refused to have “homosexual relations” with him.
The medical officer added: “I never have been happy about locating disturbed boys or young men on the landing. Brady has shown rather too much interest in them in the past.”
Brady also managed to get the prison’s welfare officer to get him homoerotic novels while he was at HMP Durham.
He was also given private tutoring by academics from Durham University in German.
The killer was also campaigning for him to get “conjugal” lists from partner-in-crime Hindley.
And he palled up with prison reformer Lord Langford as he attempted to campaign for a move to Broadmoor.
Brady used his friends-in-high-places and twisted schemes to worm his way to a comfortable life behind bars – despite a number of “hunger strikes”.
Home Office files reveal concerns of the prison’s senior medical officer at Wormwood Scrubs.
“I deplore his association with young borstal trainees and adult mentally ill patients,” they write.
“There is little change in his hard remorseless egotistical attitude. He is one of the few men to whom I would attach the label ‘evil’.”
Brady died in 2017, and body of his last victim Keith Bennett has never been found on Saddleworth Moor.