Almost 10 years ago, a couple, their daughter and a family friend disappeared from a sleepy West Australian town without a trace. The case has baffled authorities for a decade, not least because it’s been tied to a bizarre doomsday cult. With a coronial inquest set to begin in December, we look back at the story so far.

Chantelle McDougall was just 16 years old when she met Simon Kadwell in Melbourne in the mid-1990s.

At 32, the Englishman was twice her age, but the teenager was smitten with the older man and their relationship led to the birth of a daughter, Leela.

In 2003 the family moved to Nannup, a quiet town south of Perth, with a friend of the family, Tony Popic, searching for a new home for their alternative lifestyle.

Chantelle, Leela and Tony quickly integrated into the small community but Simon remained withdrawn, rarely venturing from the remote farmhouse where they lived.

While residents remembered him as odd - some described him as "controlling" - none suspected the sinister reality of the family's double-life, nor that they would soon vanish forever.

In July 2007, they left Nannup with little warning — only a late-night phone call to Chantelle's parents and a note for their landlords pinned to the door, saying they were moving to Brazil.

Their wallets, credit cards and dirty plates were still on the table, according to WA Today.

Jen Bornatici, a friend of the family, remembers Leela in a 2013 episode of Channel 10's 'Wanted' (posted continues after video...):

Six months later, with no word from their 27-year-old daughter, Jim and Cathy McDougall reported her missing, along with their six-year-old granddaughter.

The subsequent police investigation revealed 45-year-old Simon was not Simon at all.

In fact, his name was Gary Feltham and he was the leader of internet doomsday cult the "Truth Fellowship", which obeyed a set of doctrine laid out in a book he had authored titled Servers of the Divine Plan that predicted a new world order was about to emerge.

"The book itself seems to be full of standard new-age cliches and jargon,"  Adrian van Leen, a self-described 'cult-buster', told news.com.au in 2009.

"I think this is a case of a conman rather than a cult and what happens when a conman is about to be exposed or thinks he is about to exposed? They do a runner.

"Let's just hope he has taken the others with him and there is nothing more concerning to it.''

Immigration authorities have no record of the group ever leaving Australia. Their bank accounts were never touched again and while there's no evidence they were murdered, there's also nothing to suggest they may still be alive — aside from one report a man calling himself Tony Popic checked into a Northbridge backpackers on July 15, 2007.

As Nannup Shire Deputy President Robin Mellema, who's lived in the area for 37 years, told Perth Now just this week:

“People still talk about it and wonder where they could have possibly gone.

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

At a hearing at the Busselton courthouse in April, dates were set for a coronial inquest which will take place from December 6th to 8th this year.

Anyone with any information is still encouraged to contact CrimeStoppers on 1800 333 000.