Something seemed amiss. The men’s noses were assailed by the potent smell of decaying flesh.

After searching the area, expecting perhaps to find only a rotting animal, under a rocky outcrop they made a ghastly discovery, clumps of hair and items of clothing, under heaped-together sticks.

The two men cut short their orienteering run and went to the police.

They led police back to the site and the officers soon determined that the victim had been murdered. While combing the area for evidence that might lead them to the murderer, the next day another body was found.

Both were women, with multiple stab wounds, and one had been shot in the head several times as if cruelly used for target practice. Investigators knew they were dealing with a particularly callous killer.

A search of missing persons records turned up the names Joanne Walters and Caroline Clarke, British backpackers who had disappeared from Kings Cross at Easter earlier in the year.

Police soon confirmed that the bodies were the missing women.

They were only the first two bodies found in a case that became known as the Backpacker murders.

Five more victims would be discovered in the forest, murdered between 1989 and 1992, but some were not found until 1993.

But while the killer initially eluded police, he was not smart.

Ivan Milat menaces actor from inside Supermax

He had left a trail of clues that would eventually lead police to the door of a road worker with a murky past named Ivan Milat.

Born in 1944, Milat was the fifth son of 14 children born to a Yugoslav migrant and an Australian-born mother.

According to some accounts, his father was a strict disciplinarian with a fiery temper and as much as he tried to control the behaviour of his sons, they were often in strife.

From a young age Milat was a troublemaker, who left school at 15.

At the age of 17 he was convicted of theft and soon added to his police record with more convictions, some for armed robbery.

He did time in prison but as soon as he was out he was causing more trouble.

In 1971 he was brought up on charges of having raped a girl at knifepoint, after he detained her and a friend.

But the fact that one of the girls had agreed to have sex with Milat if he let them go meant he could mount a defence that it was consensual. Milat walked free.

In 1971 he faked his own death to beat another rape charge.

Police are investigating the possibility that he was involved in other murders and disappearances in 1971 and 1972 in Queensland and Victoria, before he fled to New Zealand, or on surreptitious visits back here.

His early crimes bear striking similarities to his later murders.

Milat was arrested in 1974 when he returned to Australia, after hearing his mother had suffered a heart attack.

But he also escaped the rape charges and others for armed robbery.

Two women hitchhiking from Liverpool to Canberra narrowly escaped Milat’s clutches in 1977, but they didn’t report the incident to police at the time.

It would only come out after the bodies had been found in the forest.

He is suspected of other crimes through the 70s and 80s but in 1984 he put on a cloak of respectability, getting married and settling down in a house in the Western Suburbs.

But his wife found him cruel and brutal, also obsessed with guns and knives and left him in 1987.

Then came the “Backpacker murders”.

In December 1989 Australians James Gibson and Deborah Everist disappeared while hitchhiking from Liverpool to a festival in Goulburn.

Gibson’s backpack and camera were found by the roadside in Galston, a red herring to throw police off the scent.

In 1990 British backpacker Paul Onions accepted a lift from Milat, but Milat had pointed a gun at him and told him “this is a robbery”.

Onions had a feeling Milat did not intend to let him leave alive.

The Brit fled, dodging bullets as he ran. He gave a description to police but no action had been taken when he left Australia.

In January 1991 German tourist Simone Schmidl went missing, followed by two other Germans Anja Habschied and Gabor Neugebauer in December 1991.

In April 1992 Clarke and Walters disappeared but as yet there was nothing to connect the disappearances, until the discovery of Clarke’s and Walters’ bodies on September 19, 1992.

A task force was set up and as more bodies were uncovered, police realised they were dealing with a serial killer.

While Milat was a suspect police didn’t have enough to convict him. The breakthrough came from the other side of the world.

Stories about the crimes made their way to Britain where in 1993 Onions read about the killings and contacted Australian police.

He was flown to Australia and identified Milat in a line-up. In 1994 Milat’s home at Eagle Vale was raided and Milat arrested.

Trophies of his crimes were discovered at the house.

At his 1996 trial, which ran for 15 weeks, he was found guilty on all charges.

He was given six years for his attempted murder of Onions, followed by seven consecutive life sentences for the murders of Clarke, Walters, Schmidl, Habschied, Neugebauer, Gibson and Everist.