That is the belief of Ivan Milat's nephew Alistair Shipsey.

Mr Shipsey has been in regular contact with his uncle since Milat was jailed in 1996 for murdering seven backpackers whose bodies were found in makeshift graves in the Belanglo State Forest.

The Macarthur resident said he spoke to his uncle almost weekly.

"We talk about family stuff and everyday things but we also talk a lot about the trial," Mr Shipsey said.

"He once sent me a ten page letter all about the case.

"He doesn't have dementia - he's so smart and so sharp."

However Mr Shipsey hasn't spoken with Milat since he was taken from Goulburn's supermax jail to the Prince of Wales Hospital in Randwick two weeks ago for a battery of medical tests.

The notorious serial killer and former Eagle Vale resident was then diagnosed with terminal oesophageal and stomach cancer.

Mr Shipsey said he was saddened to hear about Milat's diagnosis.

"He's in a bad way," he said.

"There was a tumour in his throat and another in his stomach and he only weighs about 62 kilograms now."

Milat is being held in a secure annex of the Randwick hospital and is expected to remain there for several days yet.

The prolific serial murderer is expected to be moved to the hospital inside Long Bay Correctional Centre at Malabar rather than returning to Goulburn Supermax where he has served most of his time behind bars.

Mr Shipsey said he had not been allowed to visit Milat in hospital but other family members including his uncle Bill and aunt Carol, his aunt Mary and his mother Diane had visited the dying man.

He said Milat had always been his favourite uncle growing up.

"I am his oldest nephew and we have always been close," Mr Shipsey said.

"He's a good person, with a big heart - he was a tower of strength.

"When my Dad committed suicide when I was 16, Ivan paid for part of the funeral and the headstone.

"He was cool, he always had cool cars and I looked up to him."

Milat was arrested on May 22, 1994 at his home on Cinnabar Street, Eagle Vale.

In 1996, after a lengthy trial, the former roadworker was given seven consecutive life sentences for murdering Deborah Everist, James Gibson, Caroline Clarke, Joanne Walters, Gabor Neugebauer, Anja Habschied and Simone Schmidl..

Milat also kidnapped British tourist Paul Onions who managed to escape from the killer's vehicle and report the crime to police.

However Mr Shipsey said Milat was innocent and hoped there would one day be an inquiry into his arrest and trial.

"He was convicted without DNA evidence," he said.

"He was convicted because of all of the things found in house that allegedly belonged to the backpackers.

"The seminal DNA found on Caroline Clarke and the skin and hair found under Joanne Walters fingernails did not match Ivan's DNA.

"I have spoken to many people including criminologists, ex-police officers and detectives who think Ivan was framed."

Mr Shipsey believes police moved quickly on Milat because the government hoped to secure the 2000 Sydney Olympics.

"They had to assure the Olympic committee that tourists wouldn't be murdered," he said.

"Ivan has always wanted to tell his side of the story but he hasn't been able to do so."

In 2014 Mr Shipsey released the Milat Letters, a self-published book featuring letters Milat wrote to him while in prison.

Mr Shipsey said his aim in writing the book was to shed some light on his uncle's views of the trial and case against him.

"I know he didn't do it and my goal is to get some closure for the families of those poor people who were murdered," he said.

Milat has never confessed to any of the crimes and Mr Shipsey said no deathbed confession would be forthcoming.

He said all reports from medical staff indicated that Milat has just a few weeks to live.

"He's still in hospital and I don't think they will be moving him from there in a hurry," Mr Shipsey said.

"I would like to visit him when he moves to Long Bay because I would like to see him before he dies."

Mr Shipsey said no funeral details had been finalised.

"We have talked about having him cremated rather than burying him as his gravesite may get vandalised," he said.

"If we do, we will find a nice place to spread his ashes."