Police in 1997 search the Bungonia state forest for murder victim Kerry Whelan. With the death of killer Bruce Burrell, it may be up to cavers to find the remains, Picture: News Corp

Stretching before them was the vast, eerie and often impenetrable area known as the Bungonia State Forest, where the bodies of not one but two murdered women lay.

At that point, the police, with their teams of divers and dogs, were only looking for the remains of 39-year-old Kerry Whelan.

The missing wife of wealthy industrialist Bernie Whelan, and the mother of his three children, was possibly secreted in some nook or cranny of the rugged terrain which abutted the prime suspect Bruce Burrell’s farm Hillydale.

At the time Burrell — who has died in prison, aged 63 — was confident that the search of his property would yield no bodies, and that without bodies he would never be convicted of murder.

What the police searchers didn’t know then was that the Bungonia forest and recreation area covered almost 4000ha, and bordered the immense Morton National Park, which was 162,000ha.

They would end up scouring vast tracts of bush, abseiling down ravines, and diving freezing dams.

Murderer Bruce Burrell boasted he had the perfect hiding place for bodies: the vast, eerie Bungonia state forest. Picture: SuppliedSource:Supplied

Debra (left) and Bernie Whelan on killer Bruce Burrell’s property in 2002 with police during a search for his murdered wife Kerry, with Bungonia National park behind. Picture: News CorpSource:News Corp Australia

Bruce Burrell, at his Bungonia property after Kerry Whelan’s disappearance boasted of knowing where to bury a body. Picture: News CorpSource:News Corp Australia

But on the first morning, hopes were high when 30 officers with two-way radios, water bottles and combat boots spaced 3m apart, painstakingly made their way along an outcrop called Nuggetty Ridge.

As they made their way deeper into Bungonia’s rocky terrain, the police encountered a labyrinth of underground passages and dozens of abandoned 19th century prospector shafts 20-30m deep.

Anyone of the holes could have contained a body.

“There are lots of caves, there are lots of tunnels and there are lots of mines,” Inspector Mick Howe said at the time.

“And each one of those mines, each one of those caves and each one of those tunnels is going to be individually searched.”

Overhead, Polair helicopters circled. Inspector Howe declared that “If it’s one week, two weeks, three weeks, four weeks — I don’t care how long it’s going to take, we will be here until the search is completed”.

A procession of police cars leave Bruce Burrell's property in 1997 when police had high hopes of finding Kerry Whelan’s body. Picture: News CorpSource:News Corp Australia

Senior Constable Roger Gough is lowered down an old mine shaft in the search for Kerry Whelan at Bungonia. Picture: News CorpSource:News Corp Australia

Dorothy Davis’s family hoped police would never give up on finding her remains. Picture: SuppliedSource:News Corp Australia

Bernie Whelan hoped police would find his wife Kerry’s body at Bungonia. Picture: SuppliedSource:Supplied

After several exhausting months, the police were forced to pack up and leave, but they would be back.

As detectives delved further into the life of Burrell, a former advertising manager at the Whelan firm Crown Equipment, who Bernie had retrenched in 1990, new information would bring them back to cold, eerie Bungonia.

Bruce Burrell used a quad bike on his property and had been seen entering the state recreation area on his bike.

Police figured he could have more easily transported and hidden a body inside Bungonia with the vehicle.

Three weeks before Kerry disappeared, Burrell had made an unexpected visit to the Whelan home.

Police believe Burrell intended to abduct Kerry on that day, but abandoned his plan after discovering her youngest child, James, was at home from school.

After Kerry disappeared, a ransom note was delivered to the Whelan’s house all typed in capital letters.

Police believed murderer Bruce Burrell could have moved bodies on his quad bike into the Bungonia forest. Picture: News CorpSource:News Corp Australia

Police made several searches of the Bungonia forest for bodies but it yielded no clues. Picture: News CorpSource:News Limited

“Follow all instructions or your wife will die,’ the letter to Bernie Whelan read. Former colleagues of Burrell’s told police that he typed his advertising copy in capitals.

When police raided Burrell’s farmhouse, they found a cache of weapons, a chloroform bottle and two obscure — but revealing — notes which suggested a kidnap and ransom plan.

Burrell had boasted to friends he could hide a body in bushland where “no one would ever find it”.

And then, a woman phoned detectives after seeing television news footage of the police convoy entering Bruce Burrell’s property.

Maree Dawes told investigators that she knew Bruce Burrell. He had been her mother’s neighbour in the Sydney suburb of Coogee two years earlier, when 74-year-old Dorothy Davis vanished.

The Sydney grandmother, who had never been found, had been trying to retrieve the $100,000 she had lent to Burrell at the time of her disappearance.

On that exact day, Marie Davis believed her mother had gone to visit a “sick friend”, Burrell’s then-wife Dallas.

It was too much of a coincidence that Burrell would know two rich women, both of whom vanished without trace.

Police Inspector Bruce Couch talks to police officers at the base camp as they searched for Kerry Whelan’s body. Picture: News CorpSource:News Corp Australia

Bruce Burrell's hayshed on his Bungonia property had no trace of kidnap victim Kerry Whelan. Picture: News CorpSource:News Corp Australia

It was not until April 1999 that police charged Burrell with Kerry Whelan’s murder, and they again searched the Bungonia property, and the forest.

Central to the area is the Bungonia Gorge, a deep chasm full of magnificent limestone caves, much appreciated by speleologists, but too steep and precipitous for ordinary visitors.

Again, the police found nothing.

In 2002, chief investigating detective Dennis Bray, who had established a close relationship with the Davis and Whelan families, organised yet another Bungonia search.

On this occasion, Bray arranged for the families to visit the site so they could see for themselves how police had not given up on finding the missing loves ones.

Maree Dawes, her brother Leesel Davis and his wife Tanna inspected maps of the terrain then spent more than an hour in 4WDs touring steep fire trails made treacherous by heavy rain.

“We’ve obviously been kept advised on each of the occasions where searching has taken place, but I think unless you come here and you see it, it is really difficult to understand how rough and rugged it is and how vast,’’ Mrs Dawes said at the site.

In 2002, Bernie Whelan and his family visited Bungonia where he said ‘cold blooded killer’ Burrell should say where he left Kerry’s remains. Picture: News CorpSource:News Limited

“The police will never give up on this. They haven’t given up on us in seven years and they certainly don’t intend to give up on us now.”

On his visit to Bungonia with his children, Bernie Whelan said “I don’t want to sound macabre, I don’t expect there to be much left of Kerry, but any clue, no matter how small ...

“The police seem confident and we’re pretty excited about it. We want to bring her home.”

The events took a heavy mental and physical toll on Bernie Whelan.

Seven years after that last search, in 2008, Mr Whelan looked every bit his 70 years.

The pain and enduring sorrow of losing Kerry, and then not being able to bring her home haunted his face.

“No one can understand what we’ve been through. Kidnapping is the cruellest of crimes,” Whelan said.

“Bruce Burrell was once my friend. He was welcomed into my home. He cuddled my children, then he betrayed me in the worst way imaginable. He’s not an insane person — he’s just a cold-blooded killer who would do anything for money.”

Bernie Whelan always hoped Burrell would one day tell police where the bodies are buried.

Now that hope has died with Burrell, who is believed to have succumbed to heart disease while serving a life sentence for murder.

For the Davis family and for Bernie Whelan’s children, the only remaining hope in vast Bungonia is that a caver, or intrepid explorer one day comes across two skeletons, perhaps in the same hiding place that Burrell once boasted of.