The father of murdered toddler James Bulger fears Jon Venables will kill another of his children upon his release from prison.
Ralph Bulger, 46, said it would be the "ultimate sexual thrill" for the convicted child killer and paedophile to murder one of James's siblings.
Bulger was describing his fears over Venables following the news he will be released from prison after being jailed for downloading child pornography in 2010.
Venables was 10 years old when he tortured and murdered two-year-old James with Robert Thompson in Bootle, Merseyside, in 1993.
He was released with a new identity in 2001. James' father now believes he will target his family again following his latest release.
Speaking to the Sun, Bulger said: "I've always believed the ultimate sexual thrill for Venables would be to go after another one of our children. He is a violent sexual predator and child killer and nothing would give him a buzz like abducting, torturing and murdering another innocent child from our family.
"He will never be able to stop his twisted lust for kids. Now he is to be released again, I will never feel safe for my family. I know he is out there wandering free again and burning with a depraved need to abuse children.
"I have no doubt in my mind that when Venables was picked up and recalled to prison, he was already spiralling out of control and on a mission to abduct and kill another child.
"They may have only been ten when they murdered James, but they also sexually assaulted and tortured him. No-one wants to accept ten-year-old boys could have had a sexual motive for the murder - it's horrific but true."
The family of the murdered two-year-old previously said they were dismayed at the decision by the Parole Board to release Venables from prison.
A spokesperson for the Ministry of Justice added: "The re-release of life-licensed offenders is directed by the independent Parole Board once they are satisfied [the offender] can be safely managed in the community.
"Their life licence lasts for the rest of their lives, and they may be recalled to prison at any time for breaching licence conditions.
"Additionally, they will be subject to strict controls and restrictions for as long as their risk requires them."