A convicted Queensland pedophile who has been linked to the disappearance of Daniel Morcombe is a ''biological psychopath'' who once bundled a 9-year-old boy into his car before violently sexually assaulting him, court documents reveal.

The ABC today reported Douglas Brian Jackway had recently been spoken to by police over the disappearance of 13-year-old Daniel Morcombe. Jackway was named by Channel Seven's Sunday Night program as a person of "prime interest" in the missing persons case, one of Queensland's most baffling.

Sunday Night revealed Jackway had been released from jail a month before Daniel vanished, and the Morcombe family today said Jackway could be placed in the area at the time.

While civil libertarians and defence lawyers have expressed concern for Jackway's safety and cast doubt over a likely prosecution, court documents show the now-32-year-old rapist has a lengthy criminal history, including an attack on a young boy he abducted from the side of the road eight years before Daniel vanished.

Having committed his first offence at age 14, Jackway is currently in a Queensland prison serving time for raping a nine-year-old girl.

By the time he was 18, and with a string of weapons, stealing and assault offences to his name, he stole his brother-in-law's car and drove to Gladstone, where he approached three young children to ask for directions on April 2, 1995.

He punched one of them in the face and snatched another boy, aged 9, while a female witness looked on.

The child was driven just 300 metres before Jackway forced him into some mangroves. During the sickening sexual assault, the boy was slapped, punched and bitten before help eventually arrived.

According to court documents, Jackway held the naked boy by the throat and threatened to cut it as witnesses tried to rescue the child, and later shouted obscenities at the victim's family as he was being led to a police car.

He pleaded guilty to attempted anal intercourse with a child under 10, taking a child under 10 for immoral purposes and three counts of indecent treatment and received eight years' jail.

An attempt by the Queensland Attorney-General to have Jackway's sentence increased to 12 years failed, despite the opinion of doctors who said Jackway was a dangerous offender with no conscience or control over his deranged sexual impulses.

The Supreme Court of Appeal's then-Chief Justice said there was evidence Jackway was ''a psychopath who may well commit further serious offences when released'', but he was freed anyway due to a "legal bungle", Sunday Night reported.

Police have refused to named Jackway as a person of interest in the Morcombe case, however, Daniel Morcombe's father Bruce today told brisbanetimes.com.au police could place Jackway on the Sunshine Coast, near to where Daniel disappeared on December 7, 2003 and were now examining his movements.

Mr Morcombe said Jackway's light blue Holden Commodore had been confiscated for speeding offences on November 22, 2003, and he had allegedly used a stolen vehicle to drive to an impound yard at Kunda Park, near Maroochydoore, to retrieve it.

Daniel had been waiting for a bus on the Nambour Connection Road at Maroochydoore between 1.30pm and 2pm on December 7 when it is believed a man in a light blue sedan stopped to speak with him.

He has not been seen since.

"25% of all sex offenders re-offend within 15 years"

.........Sarah Tofte

Mr Morcombe said Jackway's name had first come up for investigation five years ago.