The pair carried out the murders from 1963 to 1965, snatching youngsters off the street before sexually assaulting their victims and burying many of their bodies on Saddleworth Moor in the south Pennines.

When he was sentenced in 1966, the judge said he was “wicked beyond belief”.

Fifty years on, 12-year-old Keith Bennett has still never been found – despite the belief that Brady knew the location and buried him on the Moors, where he buried three others.

Brady’s death comes hours after he was again urged to “do the right thing” and reveal the location of the Keith’s body.

Keith’s mother, Winnie Johnson, had repeatedly pleaded with Brady to say where he disposed of the body before her own death in 2012.

The Brady/Hindley trial heard tape recordings of the torture of 10-year-old Lesley Ann Downey, in which she was heard begging for mercy.

The jury was also shown naked pictures taken of her before she died.

The details that came out in the trial and Brady’s refusal to accommodate Ms Johnson’s last wish led to the pair being regarded as among Britain’s most notorious serial killers.

Before his death, Brady had been a patient at Ashworth Hospital on Merseyside where he was reportedly receiving palliative care.

A court hearing in February heard he had been bedridden for the last couple of years and was terminally ill with emphysema.

Myra Hindley died in 2002.

A Mersey Care NHS Foundation Trust spokesman said: “We can confirm a 79-year-old patient in long-term care at Ashworth High Secure Hospital has died after becoming physically unwell.”

The spokesman said Brady died at 6.03pm on Monday and had been on oxygen for a while.

He added that Brady was not found dead in his room but was unable to confirm if anyone was with him when he died.

Terry Kilbride, the brother of victim John Kilbride, told Sky News that Ian Brady’s death, while being a relief to him and his family, would never take away the pain of the last 50 years.

“It needs celebrating, getting rid of him, like we did when Hindley went,” said Mr Kilbride. “We had a good drink.”

Sky’s Nick Martin, who has covered the Moors Murders cases, said: “In letters to journalists like myself… he’d hinted that he may one day reveal the truth.

“I’ve got five letters that Ian Brady sent to me over the last 15 years – and many of them were rants about his treatment at the hospital about how he wasn’t being understood, about how he was too intellectual, too clever for those who were trying to read his complicated mind.

“Deep within this was this battle between him and the victims – the families – who just wanted this one piece of information… where this young boy was buried.

“I was up on Saddleworth Moor today – it is a wild and remote place and it’s a huge place.

“The worry, of course, is that now Ian Brady has died, perhaps that very dark, murderous secret that he’s been keeping all this time will go to the grave with him.”

In a statement, Greater Manchester Police said it is not actively searching Saddleworth Moor but would never close Keith Bennett’s case.

Cold case review unit head Martin Bottomley said: “I want to stress that our aim…is to find where Keith is buried and give closure to his surviving family members so they can give Keith the proper burial they so desperately want.

“We will act on credible and actionable information that will help lead us to him.”

SKY NEWS