“Losing someone that is close to you – you’re never the same person again. I truly hope this reward will prompt someone to come forward with information that will help police find those responsible for Revelle’s disappearance.

“She was young ... She was beautiful. She was working, she was happy. She was talented. She had everything going for her. And then this happened.

“For many years, our family worked tirelessly to find out what happened to my sister – but sadly both our mother and Revelle’s father, Ivor, passed away without ever knowing what happened to their little girl.”

Ms Simpson said she hoped the reward would encourage someone to come forward and so she could finally put her sister to rest.

Minister for Police and Emergency Services, David Elliott, announced the reward for information to solve the case had been lifted from $250,000 to $1 million.

“Ms Balmain was only 22 years old, and her sudden disappearance has been deeply felt by her family and friends for more than 26 years,” Mr Elliott said.

“I am optimistic that the significant increase in the reward will help detectives obtain new information relating to Ms Balmain’s disappearance and hopefully hold someone to account.”

State Crime Command director Detective Chief Superintendent Darren Bennett said that, over the years, police and the community had worked hard to piece together what happened to Ms Balmain.

“With fresh eyes now being cast over more than two decade’s worth of statements and intelligence reports, as well as physical and forensic evidence, it is our hope that justice will be found,” he said.

Following a 1999 coronial Inquest, the matter was referred to the unsolved homicide unit for future investigation.

Last year, a formal review of the case was conducted under the new unsolved framework and assigned to a senior detective for reinvestigation under Strike Force Aramac.

Strike Force Aramac lead investigator Detective Chief Inspector Stuart Bell said his team had been working on the case for the past six months, using new forensic technology to review all available evidence.

“Revelle’s family has been campaigning for justice for more than 26 years and strike force detectives are determined to finally find the answers they are seeking,” he said.

“It is our hope that today’s reward will encourage those in the community – including Revelle’s friends and co-workers at the time – to come forward and speak with police, so we can hold those involved in her disappearance accountable.”

A coronial inquiry in 1998 and 1999 identified one of Ms Balmain’s clients, Gavin Owen Samer. The then deputy state coroner John Abernethy presided over the inquiry but could find no reason for Mr Samer to harm Ms Balmain.

“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,” he told the inquiry.

Mr Samer denied he was involved in Ms Balmain’s disappearance, telling police and the inquiry he had dropped her at a nearby pub and then gone home, watched television and fallen asleep.

When asked on Friday whether Mr Samer remained a person of interest in the new investigation, Superintendent Bennet said: “He is a person of interest and that situation will be maintained.

“We are not focused on a particular suspect in regards to this reward application and to this ongoing investigation. We are open-minded about this and all other matters of this type in a historic homicide sense. We’re happy to hear from anyone who has got information about any person related to this crime.”