The child killer, who used the name Ian Stewart-Brady, died aged 79 on May 15 this year and was incinerated without ceremony.
The body was collected from the mortuary at Royal Liverpool hospital by a Tameside Council official at around 9pm on October 25, court documents show.
Under police escort the corpse was then taken to Southport Crematorium, where the cremation began at 10pm exactly. No music or flowers were allowed.
Following this, Brady’s ashes were placed in a weighted biodegradable urn, driven to Liverpool Marina and later dispatched at sea on Thursday, October 26, at 2.30am.
The serial killer’s crimes shocked the nation as he tortured and murdered five children in the 1960s along with Myra Hindley, who died in prison in 2002.
There were fears the remains of Scottish-born Brady would be scattered on Saddleworth Moor - where they buried four of their victims.
Brady’s executor Robin Makin gave assurances there was “no likelihood” of this happening, but the Chancellor of the High Court, Sir Geoffrey Vos, ruled in October the issue of disposal should be taken out of Mr Makin’s hands.
The Moors Murderer died at Ashworth High Security Hospital in Maghull, Merseyside, having been there since 1985.
Brady and partner Hindley were convicted of luring children and teenagers to their deaths, with their victims sexually tortured before being buried on Saddleworth Moor in the south Pennines.
Pauline Reade, 16, disappeared on her way to a disco on July 12 1963 and John Kilbride, 12, was snatched in November the same year. Keith Bennett was taken on June 16 1964 after he left home to visit his grandmother; Lesley Ann Downey, 10, was lured away from a funfair on Boxing Day 1964; and Edward Evans, 17, was killed in October 1965.
Brady was given whole life sentences for the murders of John, Lesley Ann and Edward.
Hindley was convicted of killing Lesley Ann and Edward and shielding Brady after John’s murder, and jailed for life.
Both later confessed to the murders of Pauline - whose body was found in 1987 - and Keith, whose body has not been discovered.
The mother of Keith Bennett, Winnie Johnson, made repeated requests to Brady to identify where the 12-year-old’s makeshift grave was located, so she could give her boy a proper burial.
She received no reply and died in August 2012 without being able to fulfil her last wish.
An inquest into Brady’s death heard he died of natural causes.
Home Office pathologist Dr Brian Rodgers said the cause of death was cor pulmonale, a form of heart failure, secondary to bronchopneumonia and chronic obstructive pulmonary disease, or lung disease.
The court heard Brady, who was a heavy smoker up until the smoking ban, had “very severely diseased” lungs.
In a statement, Tameside and Oldham councils said: “We are pleased that this matter is now concluded and we are grateful for the support and professionalism shown... to ensure Ian Stewart-Brady’s body and remains were disposed of expediently at sea in a manner compatible with the public interest and those of the victim’s relatives.”