One of Australia’s most famous killers has died in an Alice Springs hospital, losing his battle with terminal cancer.

Bradley John Murdoch died in palliative care on Tuesday night while serving a life sentence for the roadside murder of British backpacker Peter Falconio in 2001.

Back in 2001, Falconio, 28, and his girlfriend Joanne Lees were driving about 300km from Alice Springs, when they were flagged down by Murdoch, who claimed the car the couple was driving had mechanical issues.

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Falconio and Murdoch went to the back of the car, when Lees heard a gun shot.

Murdoch has protested that he was innocent in the shooting murder of Falconio, however was found guilty in 2005 and sentenced to 28 years or life without parole.

Murdoch was also found guilty of attempted kidnapping of Falconio’s girlfriend, Joanne Lees, whose head was covered, and her hands tied, shortly after she heard the gunshot, but managed to escape into the bush and hours later flag down a passing truck.

Falconio was never seen again, and his body has never been found.

A statement released by Northern Territory police on Wednesday morning said Murdoch’s death had denied Falconio’s parents closure.

“It is deeply regrettable that Murdoch has died without, as far as we are aware, ever disclosing the location of Peter Falconio’s remains,” police said.

“His silence has denied the Falconio family the closure they have so long deserved.

“Our thoughts are with the Falconio family in the United Kingdom, whose grief continues.

“The Northern Territory Police Force remains committed to resolving this final piece of the investigation.”

Police said they continue to appeal to anyone who may have information that could lead them to Falconio’s remains to come forward, “no matter how small the detail may seem”.

Last month, police doubled their reward to $500,000 for information.

True crime author Robin Bowles revealed a conversation she had with the convicted killer a few years ago, where she claims Murdoch has something “explosive” to tell on his deathbed.

“It’s a shame they weren’t able to be released earlier,” she told 7NEWS.

“You can’t sue a dead man, so if he’s making the claims, and he’s died — the proverbial might hit the fan.”

Police have not yet confirmed if Murdoch made any confessions before his death.

Colleen Gwynne — known for her work in the arrest and conviction of Murdoch — said she wanted to see a resolution for the Falconio family “who really have been through years of distress”.

Gwynne said authorities had made many attempts to secure key information from Murdoch, and even “enticed him” with the opportunity to move to his native Western Australia to serve out his sentence.

“That’s still didn’t change his willingness to assist us,” Gwynne told 7NEWS.

The former chief investigator said it would not be in Murdoch’s character to suddenly have a change of heart.

“I think for Bradley Murdoch, he’s maintained his innocence. He’s never said to anyone that he’s guilty of this,” Gwynne said.

“I think for him, it’s a part of his control that he will never disclose — he will take it with him. It’s unfortunate for the family that’s what he’s chosen to do.”

Despite various police searches in the last 20 years, Falconio’s body has never been found.

The NT introduced a “no body no parole” law in 2016, preventing people convicted of murder from being able to qualify for parole unless they give up the location of the victim’s body.

Murdoch would have been eligible for parole in 2032.