Serial killer Ivan Milat "could last another three months", family members have claimed, after he was transferred from hospital to Sydney's Long Bay Jail to live out his final days.

Milat looked frail and gaunt as he was discharged from Prince of Wales in a wheelchair, pushed by a nurse and surrounded by Corrective Service Officers, as part of a high-level security operation just after midday yesterday.

The 74-year-old was placed into the back of four-wheel drive, which then made the 7km journey to Long Bay prison.

Unrecognisable, Ivan Milat is pushed out of Randwick Hospital in his wheelchair. Picture: Matrix for the Daily Mail (www.matrixpictures.com.au)

Ivan Milat was in handcuffs and his ankles were shackled. Picture: Matrix for the Daily Mail (www.matrixpictures.com.au)

The backpacker murderer was transferred in a convoy of two identical 4WDs with a NSW Police helicopter hovering overhead.

Once back inside, authorities were still taking no chances.

Images captured from the 9News chopper show Milat shackled by the ankles and handcuffed as he was removed from the vehicle and shuffled back into what will be his new home Long Bay jail hospital.

Serial killer Ivan Milat looks barely unrecognisable with his grey hair in a wheelchair as he leaves hospital. (9News)

Helicopters hovered overhead as Milat was pushed to a 4WD which took him back to Long Bay jail. (9News)

Earlier this month Milat had been transferred from Goulburn Supermax, his home for the last two decades, to the Sydney hospital to undergo medical tests.

Family members have stated Milat had lost 20 kilograms and is reported to be suffering terminal stomach and oesophagus cancer.

Despite that, Milat's nephew Alistair Shipsey said his family believes he is not yet near to death.

"They're saying he's got a couple weeks to live, but he's not going to die in two weeks - he could last another three months," he said.

"My mother seen him the other day and said he's okay. She said he's speaking perfect - he hasn't got dementia (sic)."

A car carrying Ivan Milat is seen leaving Prince of Wales Hospital in Randwick, Sydney, today. (AAP)

Milat could be seen in the back of a prison van during his transportation. (9News)

Ivan Milat was sentenced to seven life sentences for murdering seven backpackers in the 1990s. (AAP)

The former road worker was sentenced in 1996 to seven consecutive life sentences for murdering seven backpackers whose bodies were found in makeshift graves in NSW's Belanglo State Forest in the 1990s.