20/04/2017 7:06 AM AEST | Updated 20/04/2017 8:32 AM AEST

Police Investigate Claims Peter Falconio's Body 'Cut Up, Dumped'

An anonymous letter claims to know where the British backpacker's body was buried.

Fairfax Media
Bradley John Murdoch was sentenced to life imprisonment for Falconio's murder in 2005, but he never revealed the whereabouts of the body.

Northern Territory police are investigating an anonymous letter, whose author claims to know where murdered backpacker Peter Falconio's body is buried.

Bradley John Murdoch murdered the British backpacker in the Northern Territory outback in July 2001 in what has become one of Australia's most notorious crimes.

Murdoch was convicted in 2005 and handed a life sentence with a non-parole period of 28 years, but he never revealed what he had done with the body.

Now, the NT News says it has received a letter from an anonymous Australian expat living in London, claiming that Murdoch called in a criminal associate, who the NT News didn't name, to help dispose of the body.

"Murdoch phoned (the associate) and ordered him to fly to Darwin at once, hire a car and meet him in the Outback," the letter states, according to NT News.

Murdoch had cut the body up and put it in two large ... bags that were watertight and smell proof."

"When they met, Murdoch told (the associate) that he had murdered a guy in self-defence. At the time, (the associate) had no idea who the victim was.

"Murdoch had cut the body up and put it in two large ... bags that were watertight and smell proof."

The letter writer -- who claims the associate turned to them for advice following the murder -- said Murdoch ordered the associate to drive to Adelaide, catch a plane to Perth and then dissolve the body parts in acid and dump the remains in the Swan River. But these instructions were not followed.

Instead, the associate caught the Indian Pacific train back to Perth, believing that the two large bags containing Falconio's body would be less noticable on the train.

"(The associate) told me he couldn't even open the bags he was sick and petrified," the letter states.

Handout . / Reuters
Joanne Lees and Peter Falconio pose in their van before driving to outback Australia, where Falconio was murdered and Lees was assaulted by Bradley Murdoch on July 14, 2001.

Murdoch reportedly had connections in Geraldton (400km north of Perth) and Broome, as he was "always going up there to unload or buy stolen goods and drugs".

"(The associate) went way past Geraldton and buried both the bags unopened in a nice spot and even made up a cross," the letter reads.

"Later he realised who he had buried and was in a bad way about it.

"He knew I had a sister who worked in law and asked what I thought he would get if he went to the police.

"I told him I thought about five years for assisting Murdoch. This terrified him."

The letter writer claimed that he needed to remain anonymous, as he was once involved in criminal activity with Murdoch's associate, but he "swears" the contents of the letter are true. He says Murdoch's associate disposed of the body as he was "very scared" of him, as "Murdoch had a lot on him".

STR New / Reuters
Joanne Lees walking out of court in Darwin on December 15, 2005, where Bradley Murdoch was sentenced to life imprisonment with a non-parole period of 28 years for murdering her boyfriend and assaulting her.

The letter, which was typed on an A4 paper and sent to NT News via Air Mail, says the writer felt it was wrong of him to betray the trust of the associate "but I feel the Falconio family and his girlfriend (Joanne Lees) deserve to know what happened to their loved one".

Joanne Lees was with Falconio driving along the Stuart Highway north of Alice Springs on July 14, 2001, when Bradley Murdoch flagged them down, saying their van might have an engine problem.

Falconio went behind the van with Murdoch to investigate, then Lees heard a gunshot and Murdoch bound her with cable ties and covered her head. She managed to escape and evade capture, hiding in the bushland for five hours while Murdoch searched for her with his dog.

Police reportedly receive many letters claiming to know the whereabouts of Peter Falconio's body, but the details of this particular letter had piqued their interest, according to NT News.

"Northern Territory Police are reviewing the contents of the letter to determine whether it contains material which should be investigated further," NT Police said in a statement.