Bennett was nabbed by the couple on June 16th 1964 when he left his family home to visit his grandmother.
The young boy was lured into a van by Myra Hindley, who asked him to help her with some boxes.
Keith Bennett is the only victim of the sadistic killers to remain missing.
The bodies of three victims, Pauline Reade (16), John Kilbride (12) and Lesley Ann Downey (10), were all found during extensive searches of Saddleworth Moors.
Brady and Hindley were caught red-handed with the body of their final victim, Edward Evans (17).
News of the breakthrough in the case came after author Russell Edwards assembled a team of experts in a bid to solve the mystery.
The skull was discovered after a soil analysis of an area in the Moors indicated to the presence of human remains.
A further dig was conducted in which the skull was found. Experts believe it is that of a child aged 11 or 12. Daily Mail has reported that detectives are now preparing to exhume the area where the skeletal remains have been found.
On Thursday night, forensic anthropologists from Greater Manchester Police began examining samples of body tissue taken from the area in a bid to extract DNA.
They are also looking at a small sample of material, believed to be clothing, found buried beside the skull.
Speaking of the moment Edwards made the discovery, he told Daily Mail: “The smell hit me about 2ft down. Like a sewer, like ammonia.
“It was on my clothes I stank of it. The soil reeked. I worked as a gravedigger when I was 19 that hits you, that smell of death. It is distinctive.
“I was overjoyed. Then we found blue and white stripped material. Then I stopped. I put everything back as I found it.”
He believes that the body can only be that of Keith, however, DNA is yet to confirm whether or not the remains do belong to the young boy.
“This is about peace for Keith and closure for the family,” he said.
Ian Brady and Myra Hindley began their two year murder spree, killing five victims, in 1963 after Brady told his lover he wanted to commit the “perfect murder.”
In 1966 Ian Brady and Myra Hindley were charged for the murders of Kilbride, Downey and Evans and received life sentences under a whole life tariff.
The police investigation into the case was reopened in 1985 after Brady admitted that he had killed both Reade and Keith Bennett, something police had already suspected.
In the murders of Reade, Kilbride and Bennett, Hindley lured them by offering them a lift in her van.
She would then ask her passenger to accompany her to the Moors to search for an expensive glove that she had misplaced. Brady, travelling via motorcycle, would then meet her in the Moors where he would attack, sexually assault and kill their unsuspecting targets.
Lesley Ann Downey and Edward Evans were both lured to the couple’s home in Hattersley where they were killed.
Brady was caught red-handed killing Evans with an axe by Myra’s brother in law David Smith, who was a key witness for the prosecution.
He later moved to Galway where he ran a guesthouse with his second wife until died of cancer in 2012.
Myra Hindley died in 2002 of bronchial pneumonia, with Ian Brady dying of restrictive pulmonary disease in hospital in 2017.