Warren McCorriston a person of interest in disappearance of teens Robyn Hickie, Amanda Robinson

A serial sex offender has emerged as a key person of interest in the suspicious disappearance of two Lake Macquarie teens, which has previously been blamed on serial killer Ivan Milat

A serial sex offender, whose brutal crimes had remained under the law enforcement radar for decades, has emerged as a key person of interest in two 40-year mysteries which had long been blamed on serial killer Ivan Milat.

Warren McCorriston is a key person of interest in the disappearance of Lake Macquarie teens Robyn hickie and Amanda Robinson. Picture: https://rocketreach.co/daydream-island-resort-and-spa-management_b5d292ecf42e44b0

Warren John McCorriston, set to be sentenced in the NSW District Court on Friday for five offences relating to the assaults on three women between 1980 and 1997, was charged after police re-opened an investigation into the suspicious disappearances of Lake Macquarie teenagers Robyn Hickie and Amanda Robinson in 1979.

The two girls vanished within two weeks of each other, with the now-dead backpacker killer named as a person of interest in other police investigations dating back more than 20 years.

However, Strike Force Arapaima detectives have now discarded Milat as a suspect, and McCorriston is one of the people they wish to ask questions about the 42-year-old suspicious disappearances of the two teenagers – one of the state’s most enduring mysteries.

In 2002, then State Coroner John Abernethy found that, despite no bodies ever

being found, both girls had been abducted and murdered by person or persons unknown.

No charges have been laid over the suspected deaths of the two teenagers.

Amanda Robinson, went missing in 1979.

Ms Hickie, 18, was last seen at a Belmont North bus stop on April 7, 1979 on her way to visit a friend at a local pub.

Although she had been known to hitchhike in the past, it can be revealed that an incident in Queensland in the months leading up to her disappearance has investigators certain Ms Hickie would have only entered a car being driven by a person known to her.

McCorriston, now aged 60, was a year below Ms Hickie at Belmont High School.

Two weeks after Ms Hickie’s disappearance, 14-year-old Amanda Robinson vanished from a Swansea street as she walked home after getting off a bus from a school dance.

Amanda’s abduction occurred less than three kilometres from a Blacksmiths street where McCorriston was once accused of attempting to snatch an 11-year-old girl – also in 1979 - before the charges were dropped due to issues with the young girl positively identifying her attacker.

An undated copy pic of 18-year-old Robyn Hickie who disappeared from Belmont in 1979

McCorriston was also acquitted of a vicious sex attack on a hitchhiker in Lake Macquarie, which occurred just months after the two girls were abducted, where the victim was stripped naked and assaulted before escaping naked.

Detectives from Strike Force Arapaima, set up to reinvestigate what happened to Ms Hickie and Ms Robinson as well as the unrelated case of Gordana Kotevski, who was last seen at Charlestown in 1994, moved quickly to arrest McCorriston in late 2019 on the current sexual assault offences after identifying there was a risk of further offending.

The hospitality professional, who worked at some of Queensland’s premier hotels including Mantra Legends Hotel and Daydream Island Resort and Spa, has been in custody since being extradited more than 18 months ago.

The allegations came as part of the Strike Force Arapaima investigation, with detectives uncovering the systemic stalking and brutal assaulting of the women by McCorriston.

He has pleaded guilty to five counts involving the three women, including to inflict actual bodily harm with intent to have sexual intercourse; sexual assault inflict actual bodily harm; sexual assault knowing no consent given; maliciously inflict actual bodily harm; and common assault.

Prosecutors dropped a further 17 charges.

The disappearance of the two teens had previously been blamed on Ivan Milat. Picture: Supplied.

During a sentence hearing earlier this month, McCorriston attempted to offer his “most humble apology” to the three women.

“I’m remorseful, more so that it has impacted on them, they did not deserve to be treated in such a manner, I hope they can move on,” he told the court.

And directing to one victim in particular, a woman who he had repeatedly raped, he told the court he owed her so much.

“It is due to her that I ceased being a very immature man, a delinquent who was on a path to nowhere,” he said.

“Through her support it allowed me to find a career path and purpose in life.

“At the time I was under enormous pressure and wasn’t coping and I lent on her as a crutch in hard times without talking to her about my issues.”

But any suggestion that McCorriston had mended his ways is in stark contrast to the concerns of Strike Force Arapaima detectives who decided they needed to act quickly because of concerns he was a threat of continuing to assault women he had met on various dating websites.