A $250,000 reward has been offered for information on the 1964 suspected murder of Queensland man Vincent Raymond Allen in a renewed push to solve the enduring cold case.
Mr Allen — an associate of convicted killer Vincent O'Dempsey — was 22-years-old when he was last seen in a Holden sedan on Grafton Street at Warwick, a town in southern Queensland, on the afternoon of April 18, 1964.
Detective Inspector Damien Hansen of the Homicide Group said police believed Mr Allen was murdered and had identified a person of interest in the case, which he said was "solvable" after 55 years, but would not provide details.
He said Mr Allen was supposed to play a game with the Eastern Suburbs rugby league team on April 19, 1964, but never turned up.
Detective Inspector Hansen said police wanted to hear from a member of the public who had a conversation with one of Mr Allen's teammates in the dressing sheds that day.
"That conversation concerned what we believe is the murder of Mr Allen and we ask anyone who has that knowledge of that conversation or was present to make contact with us," he said.
"We spoke to surviving people who were playing in that team ... obviously that conversation has come back to us."
He said Mr Allen had been assisting police over "two significant break and enters" of jewellery stores in the Warwick area before his disappearance.
"Two offenders were arrested for that, [but] as a result of Mr Allen's suspected murder he was unable to give evidence and those charges were dropped," he said.
Police Minister Mark Ryan said the State Government was offering a $250,000 reward for information leading to a conviction.
"Today we ask for help from the community, from people who might know.
"We ask those people to come forward, to do what's right, to let justice be done," he said.
"We want to catch the person or people who were involved in the murder of Mr Allen.
"This is a crime that happened many, many years ago, but we never give up."
Detective Inspector Hansen said the reward also provided indemnity "for any person who may have assisted in any way".
"It's a situation — and we see this in cold cases — that passage of time. People aren't as loyal to people, people aren't as fearful as they once were in coming forward," he said.
"We'd certainly be asking that anyone who has the information to come forward."
Mr Allen would have turned 77 this year.
