A man who claims he was violently sexually abused by Raymond Jones - the prime suspect in Victoria’s most baffling cold case - has told 60 Minutes that he believes his tormentor was capable of murder.

In an emotional interview, Mark Affleck, 59, revealed to 60 Minutes the sordid sexual abuse he allegedly suffered at the hands of convicted pedophile on the banks of Victoria’s Avoca River in 1968.

“He had his fishing rod and tackle box sitting (on the concrete) when he took his pants off,” Mr Affleck told reporter Tom Steinfort.

“He grabbed me by the hair and shook me that hard by the shoulders, I could feel the bone hitting with my head rocking backwards and forwards.

“I don’t know how anyone didn’t hear me, I was crying for my mum.”

Mr Affleck’s allegations could provide police with a much-needed breakthrough in one of Australia’s longest running and most baffling cold cases.

Jones remains a person of interest in the 1975 disappearance of Victorian schoolboy Terry Floyd.

Twelve-year-old Terry disappeared while walking along the Pyrenees Highway between Avoca and Maryborough on June 28, 1975.

He had spent the afternoon playing monopoly at a friend’s house and was expected to be home for dinner, when it’s presumed he was abducted and killed.

Terry Floyd was seen by two locals, at separate times, standing near a light-coloured Holden panel van on the Pyrenees highway.

Their description of the van is similar to the vehicle driven by the then 23-year-old Jones.

When asked by Steinfort if Mr Affleck thought Jones was capable of killing Terry Floyd, he answered; “Capable? Yes.”

It’s a sentiment shared by former homicide detective Ron Iddles, who believes Jones is most likely involved in the schoolboy’s disappearance.

“He was on bail for sexual assault, he has a vehicle similar to what was seen, there's about an hour and a half that he can't account for,” Mr Iddles said.

“So he is a suspect and remains a suspect.”

Mr Iddles took over the investigation into Terry Floyd’s disappearance in 1999.

He says that it’s Jones’ previous conviction – for an opportunistic sexual assault of an 11-year-old boy in a Ballarat toilet block – shares striking similarities to the Terry Floyd case.

“The assault on the boy in the toilet block, it was a sudden urge,” Mr Iddles said.

“This wasn't sort of a planned thing. 

“[Then] you've got Terry Floyd who's walking down the road hitchhiking.

“If Jones is responsible, it's like that again, a sudden urge has come over.”

In an incredible revelation, Mr Iddles told Steinfort that he gave Jones the chance to eliminate himself from the Terry Floyd investigation years ago - but Jones declined.

“I offered him a polygraph,” Mr Iddles revealed.

“I said, ‘If you pass you'll never see me again, right? If you fail, I can't use it in evidence, right? It's a win-win for you.’

“Here is an opportunity where he could have eliminated himself, and he doesn't.

“I just think that adds to the weight that he is the most likely person responsible.”

When approached by 60 Minutes as part of this week’s investigation, Jones again exercised his legal right to silence.

It was a bitter moment for Terry’s brother Daryl Floyd, who has spent the last 43 years searching for answers pertaining to his brother’s whereabouts.

Mr Floyd believes Terry was abducted and murdered before his body was dumped in a disused mineshaft.

So adamant are Mr Floyd’s beliefs that he has spent every weekend for the past eight years digging out a disused mineshaft at Bung Bong Hill is an effort to find his brother’s body.

“This is basically where all our information leads us to,” Mr Floyd told reporter Tom Steinfort.

“I believe he is down here.

“(There’s) a lot of sadness, thinking this is maybe where Terry’s last resting place could be.”

Mr Floyd was 10 at the time of his brother’s disappearance.

It’s a heartbreaking reality that has taken a heavy toll over the years.

“Every year I think that we should be off fishing,” Mr Floyd said.

“We did it as kids. But that was taken away.”

In the many hours spent at the mineshaft over the years, Mr Floyd has made tiny discoveries that spur him on in his pursuit of the truth –  including the unearthing of a 1970s-style silver chain which is an exact match to the one his brother used to wear.

“What we are finding are significant to what he was wearing on the day,” Mr Floyd said.

“Shoe, necklace, parts of clothing, a piece of elastic out of a small pair of kid’s jocks.

“[It’s] hard yakka, physically. Hard yakka, emotionally.”

Despite the hours of toil, Mr Floyd says that he will spend rest of his life to making sure the truth of his brother’s murder is uncovered.

“The buck stops with me, that's why I do this,” Mr Floyd said.

“My brother does not deserve to be laying in that disgusting mine out there.

“I made my parents a promise that we would find him, and I’m going to honour that promise.”

As for Mr Affleck, he hopes that by breaking his silence will in some way assist Mr Floyd in his dogged quest for answers.

“I hope Daryl finds his brother, I really do,” Mr Affleck told Steinfort.

“I would like to see [Jones] brought to account.”

If you have any information regarding the disappearance of Terry Floyd, please contact CrimeStoppers 1800 333 000.

To watch ‘Digging for Answers’ and for more on 60 Minutes, head to 9Now.

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