The haunting mystery of 22-year-old Sydney model Revelle Balmain's disappearance.

When Revelle Balmain was four years old, she found her baby brother, Matthew, floating in her family’s backyard swimming pool.

In light of the ‘secret life’ she would go on to lead in her early 20s, Revelle’s mother Jan believes she never fully recovered from the trauma. It’s an event Jan recalled to the Coroners Court in 1999, when she was given the opportunity to speak publicly about the loss of her daughter.

“I don’t believe she is alive,” Jan added. “I believe she has been murdered. Her life has been taken from her, so quickly and so unacceptably.”

“We need an opportunity to say goodbye.”

It was a Saturday morning in November, 1994, when Jan Balmain started to feel something was very wrong. She was waiting at a Newcastle train station for her 22-year-old daughter to arrive from Sydney, to have lunch before Revelle flew to Japan for six weeks. When the train arrived, however, her blonde-haired, blue-eyed daughter wasn’t there to meet her.

The previous day had been Revelle’s last day of work before her trip. Her parents, Jan and Ivor, didn’t know that at the time, the model and aspiring dancer was working for two separate escort agencies. It’s also believed Revelle was a frequent cocaine user, and that her plan to go to Japan was an attempt to escape Sydney’s ‘seedy’ world of drugs and underground sex work.

On Friday November 5, 1994, Revelle was working for escort agency Select Companions, and had a 4pm appointment with a man named Gavin Samer. She then had a booking with two associates of Zoran Stanojevic, the co-owner of the agency.

This is where the details get murky.

It appears Revelle never made it to her second assignment. In a statement to police, obtained by The Good Weekend in 1999, for an investigation by Caroline Overington, Gavin Samer said he entered into a private agreement with Revelle after their official appointment ended. Once this was over, he said, he dropped her off at the Red Tomato Inn in Kingsford, before returning home alone.

The last known contact Revelle had with anyone close to her was a phone call to her best friend Kate Brentnall at 7.15pm. She told her she’d call when she got home in an hour and they’d meet up for drinks. Kate, however, never heard from, or saw, her best friend again.

In the days following Revelle's disappearance, police found curious pieces of evidence in Kingsford. One of the shoes she was wearing that night, a cork platform shoe, was located in a rubbish bin, and her house keys and diary were found on the street.

A coronial inquest into Revelle's probable murder, held in 1999, identified Gavin Samer as the main person of interest.

His girlfriend at the time, Michelle Oswald-Sealy, who was in Brisbane on Friday November 5, told the inquest she had called Samer several times that night, and he eventually answered the phone at 9.22pm.

When he picked her up from Sydney airport two days later, she noted he had scratches on his neck and finger. She also noticed her partner's car had been cleaned out, and he had washed and hung out their bed sheets.

At the inquest, deputy state coroner John Abernathy said: "While Mr Samer certainly had the opportunity to kill Ms Balmain, and rightly in my view is the main person of interest to police, there is no plausible motive proved."

There was, however, another haunting account shared in evidence to the Coroner. A man named Jeremy Coghlan said his close friend Mark Coulton, a client of Revelle's, had told him the escort had been murdered.

In a statement obtained by The Good Weekend in 1999, Coghlan said, "he... said something like, 'Aren't people gullible and stupid? You've heard the story about Revelle Balmain ... First there was a story about an Arab prince who took her back to Saudi Arabia ... what a load of crap. She's 10 foot under and no-one will find her body. That's what you get for moonlighting and ripping off the brothel that she worked for, and drugging clients . . . stealing all their money. Basically, the owner of the brothel wanted her dead because she was destroying his business ... I knew her, and she was a nasty little gold digger and coke addict that would do anything for money."

Coulton dismissed the statement as "complete rubbish," saying he had heard rumours, but didn't know what had happened to Revelle.

Alarmingly, the accounts of Select Companions owners, Jane and Zoran Stanojevic, about where they were on Friday November 5 were highly contradictory. Police decided at the time, however, that their statements were satisfactory, and that they were not significant persons of interest.

At the conclusion of the 1999 inquest, the coroner laid no charges.

In 2008, Revelle Balmain's cold case was re-opened, along with hundreds of others, that police believe warrant re-investigation in light of new technologies or unexplored lines of inquiry. At the time, it was reported that forensic evidence had "added weight" to theories Revelle was murdered at the Kingsford home of Gavin Samer.

Almost 24 years after Revelle Balmain's disappearance, her mother Jan, now in her 80s, waits for updates from NSW Homicide Squad’s Unsolved Homicide Team. Revelle's father, Ivor, died in 2010, never knowing what happened to his daughter.

To this day, the 22-year-old's body has never been found.

The current reward for any information about Revelle's disappearance stands at $250,000. You can contact Crime Stoppers on 1800 333 000.