The family of murdered backpacker Peter Falconio say they feel like a weight has been lifted after hearing that the man convicted of his murder is now dead.

Notorious outback killer Bradley John Murdoch, 67, took his last breath on Tuesday in palliative care in the Northern Territory, following a battle with terminal cancer.

WATCH THE VIDEO ABOVE: Peter Falconio’s family speaks out after Bradley John Murdoch dies.

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Murdoch, 67, was jailed for life over the 2001 roadside execution of Falconio and the assault and attempted kidnapping of the traveller’s girlfriend, Joanne Lees, on the Stuart Hwy north of Alice Springs.

“Upon hearing that Bradley John Murdoch had died, our first feeling was of relief. It’s like a weight that’s been lifted,” his parents Luciano and Joan Falconio told 7NEWS in a statement from the UK.

“We are only forced to think about him now that he’s died, we don’t want to let him ruin our lives more than he already has.

“The awful thing is our family’s future with Peter was cruelly taken away.

“Today we instead focus on the three children we have left and our grandchildren.”

Falconio’s body has never been found, and Murdoch has left the family without answers.

“We didn’t have much faith, but we were hoping Bradley John Murdoch would reveal where Peter was before he died,” Falconio’s parents said.

“But even now we still hold out hope that his remains will be found.

“Finally, we wish to express our profound thanks to the Northern Territory Police for the support and continuing efforts to investigate our son’s murder.”

A statement by NT Police on Wednesday said Murdoch’s death had denied Falconio’s loved ones any 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.”

Murdoch’s family meanwhile say the man who partly inspired horror movie Wolf Creek was “deeply loved” and a “gentle giant with a heart of gold”.

“To many, Bradley Murdoch is known only for the events that led to his conviction in 2005 for the murder of British backpacker Peter Falconio, a crime for which he has always denied responsibility from his arrest until his death,” relatives said in a statement issued through lawyer Christopher Dale.

“But to those who truly knew him, he was much more than the headlines.

“Brad was a devoted father, father-in-law, and proud Poppy who never missed a chance to brag about his grandchildren.

“He was a beloved brother, uncle, and friend.”

Falconio and Lees had been on a trip of a lifetime when Murdoch drove up behind the couple, urging them to pull over near the remote town of Barrow Creek because their campervan had mechanical issues.

After shooting Falconio, he cable-tied Lees and covered her head but she managed to escape into bushland where she hid for several hours before flagging down a truck driver.

Lees said she had suffered from the trauma of the incident and the unanswered question about where exactly Falconio’s body is.

“Pete lost his life on that night but I lost mine too,” she said in a 2017 interview.

Colleen Gwynne, a former detective who helped bring Murdoch to justice, is “absolutely convinced” the right person was convicted.

“The investigation was complex, it was detailed,” Gwynne told 7NEWS.

True crime author Robin Bowles spent more than 50 hours interviewing Murdoch in jail and is on his side, believing he was innocent.

“I just think that Murdoch was caught up in this desperate effort to not have another Lindy Chamberlain on their hands,” Bowles told 7NEWS, referring to the case of a woman falsely convicted of killing her baby daughter.

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

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