The death of seven-year-old Mark Tildesley has remained a mystery almost 40 years after his disappearance in 1984.
His body was never found, but detectives believed he was one of 17 boys raped and killed by members of a paedophile ring led by one of Britain’s most notorious criminals – Sydney Cooke.
Cooke and his gang, known as the ‘Dirty Dozen’, are suspected of the abduction and killing of 17 boys in the 70s and 80s. Many of these remain unsolved.
Operating from a flat on the Kingsmead estate in Hackney, east London, the gang hired rent boys or snatched children off the streets and subjected them to sexual torture.
Cooke travelled the country preying on vulnerable youngsters, setting up his children’s Test Your Strength machine in fairgrounds and using this as an opportunity to lure boys before drugging them and subjecting them to brutal assaults.
The gang’s horrendous crimes are set to be put under the spotlight almost 40 years on from Mark’s disappearance in a new documentary airing on C5 later tonight.
Sidney Cooke, 96, (pictured) will remain in jail after the Parole Board decided he still presents ‘a very high risk of serious harm to children
Cooke was linked to the disappearance of seven-year-old Mark Tildesley (pictured) in 1984
He has been linked to some of the most horrific child sex murders in the last 50-years through his association with Dirty Dozen members Leslie Bailey, Robert Oliver and Steven Barrell.
The gang paid £5 each to rape another schoolboy named Jason Swift, who vanished from his East London home in 1985. In November that year, Jason’s naked dead body was found on a farm in Essex.
For his role in the killing, Cooke was convicted of manslaughter and sentenced to 19 years in prison.
Dirty Dozen members Leslie Bailey, Robert Oliver and Steven Barrell were also convicted for Swift’s murder.
Meanwhile, Bailey was convicted in 1992 of the manslaughter of Mark, but the youngster’s body was never found. He is thought to have been raped in Cooke’s caravan while visiting a fairground near Wokingham, Berkshire, in 1984.
Bailey was also convicted of the murder of Barry Lewis, six, who was abducted in June 1991 before being sexually abused by up to eight men.
Leslie Bailey (pictured) was jailed alongside Sidney Cooke in 1989 before he was murdered in his prison cell in 1993
Cooke is still in jail. Bailey was murdered in his prison cell in 1993 and Oliver was last reported to be living in a bail hostel in Guildford, Surrey. The whereabouts of Barrell are unknown.
Cooke was released from jail in April 1999, after serving nine years for the manslaughter of teenager Jason in 1985.
After his release he was immediately taken into voluntary custody for his own safety. However detectives, convinced he was responsible for other similar unsolved crimes, kept his file open.
Within months Cooke was accused of abusing two teenage brothers he befriended while working on fairgrounds more than 30 years ago. He was also accused of the rape of a young woman.
In an unexpected move during his 1999 trial at Manchester Crown Court, Cooke suddenly changed his plea to guilty and admitted ten offences against the youngsters and subsequently received two life sentences.
Four charges of rape, a further three of indecent assault and one of buggery were left on the court file.
Cooke was convicted of manslaughter in 1989 over the death of 14-year-old Jason Swift (pictured) in 1985
Robert Oliver (pictured) was jailed for the manslaughter of 14-year-old Jason Swift alongside Sidney Cooke, Leslie Bailey, and Steven Barrell
In March 2023, Ex-detective David Bright, who got Cooke to confess to the murder of Jason Swift, urged officers to quiz Cooke over unsolved murders before he died.
Mr Bright, who does not believe Cooke should be freed from prison, claims Cooke’s age could prompt him to ‘clear his conscience’.
‘There are other children in graves hidden around the country that could have been the result of Cooke and his former cronies,’ Mr Bright, a former Essex Police officer told The Mirror.
‘At 96 and with all but two gang members dead, he might want to clear his conscience and tell all’.
