A man has told A Current Affair of his narrow escape from a man he believes was serial killer Ivan Milat.

Ian Hayman was just 15 when he was sacked from his job as a strapper at Warwick Farm Racetrack in Sydney, in 1971.

He decided to hitch-hike home to Wollongong.

Ian Hayman claims he was picked up by Ivan Milat while hitch-hiking. (A Current Affair)

"That's when two guys pulled up in an old two-tone Holden and asked me where I was going," he told A Current Affair Crime Editor Simon Bouda.

"I told them Wollongong, and they said 'Yep, jump in, we're heading that way'."

He said what started out as general conversation soon turned to talk of Mr Hayman's family and their knowledge of his movements.

Hayman said Milat (pictured) had a companion in the car. (A Current Affair)

Mr Hayman said he did not feel threatened at that stage.

"It just seemed a little strange because as we were driving along the Wollongong turn-off was there, and the Canberra turn-off was there, and they took the Canberra turn-off," he said.

He said the passenger, who had done all the talking so far, told Mr Hayman they knew the road, and the driver continued driving.

Mr Hayman was just 15 when he encountered the man he belives was Ivan Milat. (A Current Affair)

But when Mr Hayman told them his older brother was a paratrooper in the army, the passenger said the driver - who Mr Hayman claimed he addressed as "Ivan" - had also been in the army.

"And then (the driver) looked at me in the rear vision mirror, it was just horrifying," he said.

He said the driver's eyes were "scary as hell, like black, dark".

Mr Hayward was able to sketch the driver's eyes from memory. (A Current Affair)

Mr Hayman also noticed a revolver in the open glove-box - a "cowboy revolver" of the kind favoured by Milat.

"(The passenger) said, 'they know he's coming', and the driver said, 'no they don't', and he said 'yeah, his mum, they know he's coming'," Mr Hayman said.

"And that was when he got all aggro and just slammed the brakes on and pulled over and told me to get the - out of the car."

Milat favoured a "western style" revolver. (A Current Affair)

Mr Hayman grabbed his bags and scrambled out as the car sped off with the door still open.

He crossed the Hume Highway to try to hitch a ride back towards the Wollongong turn-off, but his ordeal wasn't over.

Within "five minutes" the two-tone Holden was back, and pulled up about 100 metres further on.

Milat is now serving seven consecutive life sentences in prison. (A Current Affair)

"I thought, 'what's going to happen here?'" Mr Hayman said.

"Probably at the time, not overly sure, but I was probably ready to run in case they did pull the gun out."

Luckily, at that moment, a car driven by a priest pulled over to pick Mr Hayman up.

Mr Hayman said he was certain the driver was Ivan Milat. (A Current Affair)

For nearly three decades Mr Hayman didn't give the chilling encounter much thought, until he saw a documentary about the Backpacker Murders.

"My heart rate was just skyrocketing, I was pale," he said.

He said he was totally certain the driver was Milat.

A two-tone car was found it one of Milat's relative's properties. (A Current Affair)

Mr Hayman also believes he knows the identity of the passenger on that day, but it cannot be revealed for legal reasons.

Still, Mr Hayman believes his experience might show Milat did not always act alone.

When police swooped on Milat in 1994, they searched several family properties, finding at one a brown and white Holden. Milat was known to use his brothers' cars.

Clive Small led the task force that charged and convicted Milat. (A Current Affair)

Clive Small, who led the task force that charged and convicted Milat over the murders of seven backpackers whose bodies were found in the Belanglo State Forest, said he believed Milat was active in 1971 and there were unsolved cases involving him.

In 1971, Milat was arrested and charged with abducting two girls and raping one of them, but he beat the charges.

But Mr Small suspects Milat may have been involved in at least three other murders - those of Keren Rowland, Peter Letcher, and Dianne Pennachio.

Mr Small believes Milat is linked to other murders. (A Current Affair)

Rowland, 20, vanished after she ran out of petrol near Canberra in 1971.

Her body was found in Tallaganda State Forest, covered in branches.

Letcher was found dead in bushland near Jenolan Caves, after last having been seen alive hitch-hiking from Liverpool in Sydney's west.

Milat worked on the Jenolan Caves Road, where a body was found. (A Current Affair)

He had been shot five times in the head with a weapon similar to that used to kill some of the backpackers. Milat had worked on the Jenolan Caves Road.

In 1991, Pennachio, a mother of one, was stabbed to death.

The 29-year-old was intending to hitch-hike from Bungendore, in the NSW Southern Highlands, to her home in Queanbeyan.

Mum Dianne Pennachio was found stabbed to death. (A Current Affair)

"There were similarities to the backpacker investigations, murders, then in terms of being stabbed with the knife," Mr Small said.

However, he believes Milat carried out his killings alone.

"While my view is simply that I believe the evidence shows Ivan was acting alone, I would not be completely disregarding the possibility that another member of the family could have been involved in one or more of the killings," he said.

Milat now has terminal cancer. (A Current Affair)

Milat had eight brothers, "a number of whom", Mr Small said, had committed "serious criminal offences together".

But the brothers have always denied any involvement in Ivan's murders.

Now, with Milat's days numbered due to terminal cancer, Mr Small called on him to finally speak up about his crimes.

"This will make no difference to your life," he said in a message to the serial killer.