SIMON Kadwell was the shadowy leader of an internet doomsday cult called the Truth Fellowship. To his followers he was known simply as “Si”.

There were only 40 devotees worldwide, but they referred to themselves collectively as “The Forecourt” and connected online in a forum dubbed “The Gateway”.

The cult members obeyed a booked written by Si called Servers of the Divine Plan and its pages prophesied the birth of a new world of higher consciousness at the end of a 75,000-year cycle.

It sounds more like a script for a B-grade Hollywood movie but in fact it’s a true story, stranger than fiction, set in the sleepy timber and country music town of Nannup in WA’s South West.

From his computer inside a ramshackle, rented fibro house in Nannup, Si — when he wasn’t surfing the net — ran his online cult.

But in 2007, the 45-year-old disappeared along with his younger girlfriend Chantelle McDougall, the couple’s daughter Leela, aged six, and their friend, 42-year-old Tony Popic, who lived in a caravan parked outside the house.

It sparked a mystery that led police across the State and eventually all the way to Brazil to find answers that remain elusive to this day.

Camera Icon Missing Nannup Family. House where Kadwill and his family lived in WA. Credit: PerthNow

But all that could be about to change after the WA Coroner’s Office this week confirmed it would hold an inquest in December into the disappearance and “suspected deaths” of the four.

Ms McDougall’s parents, Jim and Cathy McDougall, are among the family members desperate for answers and hopeful the inquest will shed new light on the case.

Kadwell and his young family had moved into the Nannup property in 2004 and he quickly became known to locals as an oddball. They soon became familiar with his noisy tirades about a perceived conspiracy against Leela and himself involving electromagnetic waves being diverted towards their home.

Camera Icon Simon Kadwill, who was also known as Gary Feltham. Credit: PerthNow

His neighbour Bruce Blackburn previously recalled Kadwell “ranting and raving”, strung out and paranoid as he went on about harmful electromagnetic fields.

Life next door to the strange Englishman had become difficult due to Kadwell’s extreme reaction to plans by utilities company Western Power to install a nearby power pole with a transformer, which he thought was the source of electromagnetic waves.

“Simon was paranoid about electromagnetic fields. He was always ranting and raving about them, up to the point where he was breaking out in hives and his face looked as if it was about to burst, it was so red. This went on for four months,” Blackburn said in 2015.

His description paints his neighbour as a Jekyll and Hyde character plagued by irrational fears.

“He began burying a heap of magnets around the place because he believed they diverted these rays away from him. I went up there once and he was yelling at Tony (Popic), who was digging away in the backyard, trying to find the magnets,” Blackburn said.

“The second last time I saw him he was covered in hives. He said they were killing him and his daughter, and he had gone to the doctor to get some sort of medication. He and Tony were off the planet.”

Soon after these encounters, in July 2007, Kadwell, Ms McDougall, Leela and Popic drove away from their Nannup residence forever. They left behind wallets, credit cards and dirty plates on the table. A note scrawled with the words “Gone to Brazil” was found stuck to the front door by their landlord a few days later.

It was only after the family became the subject of a national, then international police search, that Kadwell’s ties to the doomsday cult emerged, along with the revelation that “Simon Kadwell” was actually Gary Feltham. According to investigators, Feltham had stolen the identity of a former associate in the 1990s and assumed his name.

Camera Icon Missing Nannup family. (L-R) Chantelle McDougall, internet doomsday cult leader Simon Kadwill, aka Gary Feltham, Tony Popic and Leela McDougall (6yo). Credit: PerthNow

The last official sighting of the four was on July 13, 2007 in Busselton, about an hour’s drive from Nannup. There, they sold a car to a local dealer for $4000 and drove away in a waiting vehicle.

At the time, Popic’s father Joe told police he had recently given his son $25,000 to take care of what he had believed to be a “legal matter”.

Police initially thought that they may have sneaked out of the country to New Zealand before travelling to Rio Branco, a Brazilian city known for its religious cults that both McDougall and Kadwell mentioned in conversation before they vanished.

But immigration authorities have no record of the group leaving the country and their bank accounts have remained untouched, raising fears the four were dead, possibly even murdered.

That theory continues to be rejected by Ms McDougall’s parents, who believe their missing daughter, who was 27 at the time she disappeared, and her internet cult leader boyfriend are still alive and hiding somewhere in Australia.

Their daughter met Kadwell when she was babysitting for his child in Victoria and eventually they became a couple, moving to WA and having Leela.

Camera Icon Kath McDougall and Jim McDougall display posters of Chantelle McDougall and Leela McDougall. Credit: PerthNow, Martin Philbey

In 2010, three years after the disappearance, the McDougall’s visited Nannup in a desperate attempt to speak to residents and try to generate new leads.

“I think he’s probably got them hiding somewhere while he is up to his usual tricks of getting money off people by scamming them over the internet with this cult stuff,” Mr McDougall said at the time.

The couple accused the cult leader of brainwashing and seducing their daughter when, as a 17-year-old, she started babysitting for him.

Mr McDougall has said he believed his daughter and granddaughter feared Kadwell and were too scared to contact him.

In 2011, the investigation took a dramatic turn when it emerged police were trying to find out whether the four had indeed made it to Brazil and were aboard a Brazilian domestic flight which crashed four days after they went missing in 2007, killing all 192 on board.

The Tan Airlines flight 3054 from Porto Alegre to Sao Paulo veered off the end of the runway at Sao Paulo Airport, cleared a highway bordering the inner-city airport, slammed into a fuel depot and burst into flames. The resulting heat was so intense that more than 70 of the bodies were so badly burnt they were either never recovered or could not be identified.

Camera Icon Tony Popic’s caravan , which was parked out the front of Simon Kadwill’s house. Credit: PerthNow

However, eventually a joint investigation between Australian and Brazilian authorities concluded the four had not been aboard, and investigations into cults in the Rio Branco area also turned up no sign of them.

The case appeared to have hit a dead end but two years later, in 2013, it was back in the headlines when WA Police announced a possible breakthrough.

Det-Sen-Sgt Greg Balfour revealed four years ago how investigators had discovered that a man using Popic’s identification visited Perth and stayed at Northbridge hostel Underground Backpackers on the night of July 15, 2007, just days after the last sighting of the missing four.

His driver’s licence with his photo was also used as identification to rent the double room.

The same man travelled by train from Bunbury to Perth earlier that afternoon before catching a 7.15am train to Kalgoorlie the next morning. There was no evidence to suggest Chantelle and Leela McDougall had been on the same train.

Camera Icon The main street of Nannup, where the mystery began. Credit: PerthNow

The man could have been Popic but it was also possible Kadwell, with his history of identity theft, had posed as his friend, police said.

Despite high hopes of a more significant breakthrough, an appeal to the public for anyone who may have seen the man produced no further leads.

At the time, Sen-Sgt Balfour described the case as “truly a mystery”.

“It’s such a bizarre story and we have as little an idea of their whereabouts today as we did in 2007 when they disappeared,” he said.

The detective said it was impossible to rule out murder but said: “There’s no evidence to suggest they are dead, just as there’s no evidence to suggest they are alive”.

“We know that Tony was very protective of Chantelle and Leela but we also know they were obedient, submissive to Kadwell. He had a very persuasive way of talking and I think if he had suggested something they would have gone along with it,” he said.

Camera Icon Leela McDougall was just six years old when she vanished. Credit: PerthNow

“Remember, he successfully isolated Chantelle and Leela from their families so it’s perfectly possible they are alive, living off the grid somewhere in Australia or overseas. There are other ways to leave the country, they could have left by boat, or on a yacht.

“There are so many possibilities, so many uncertainties. Even the facts raise more questions than answers.”

Nannup Shire Deputy President Robin Mellema, who has lived in the South West town for 37 years, said the case remained one of the region’s most puzzling police investigations.

“People still talk about it and wonder where they could have possibly gone,” the 62-year-old said this week.

“It’s one of those stories where people wonder what really happened.

“There’s no answer that we can see. It’s an unusual one in that they disappeared without a trace.”

With the 10th anniversary of the disappearance looming, WA Police said it was an “ongoing investigation and continues to be investigated as a missing persons’ case”.

However, the Coroner’s inquest set down for December proves authorities also suspect the four may be dead.

While the unanswered questions are a daily agony for Jim and Cathy McDougall as they wonder at the fate of their daughter and granddaughter, they also hope the inquest may led to answers.

“We just want to know. Whether it’s good news or bad, we just need to know,” Mrs McDougall said.

Anyone with information about the whereabouts of Chantelle and Leela McDougall, Tony Popic or Simon Kadwell, aka Gary Feltham, can contact CrimeStoppers on 1800 333 000.