Daniel Morcombe murder: Prisoner admits torturing child killer in jail with bucket of boiling water

'He had it coming, he's a f****** grub,' says vigilante

Paedophile Brett Peter Cowan is serving a life sentence for the murder of 13-year-old Daniel Morcombe (Queensland Courts)

A prisoner who admitted torturing the killer of a 13-year-old boy has been given a three-year jail sentence by an Australian court.

Adam Paul Davidson, 30, pleaded guilty to torturing Brett Peter Cowan by pouring a bucket of boiling water over his head.

Cowan, a paedophile who is serving a life sentence for the murder of Daniel Morcombe in 2003, sustained serious burns to his head, chest and legs.

When Cowan stood up, Davidson hit him “three or four times” with the bucket.

Prosecutor Mark Whitbred told the court Davidson attacked Cowan from behind while he was playing a game of cards at Walston Correctional Centre in Wacol, west of Brisbane.

He said the intention was to harm, but not kill, the child-murderer.

The court heard Davidson told officers: "I did it... he had it coming, he's a f****** grub", ABC News reported.

The prosecutor said Davidson later admitted to the crime to officers and described it as "a vigilante act" on Daniel's behalf.

Sentencing him, Judge Ian Dearden said Cowan was already being punished by being in prison and he should not have been abused.

He quoted Mahatma Gandhi, saying: "An eye for an eye makes the whole world blind."

Davidson has already served almost 11 months in prison for the attack and is due to be released on parole next month.