A $250,000 reward is being offered by the WA government for information that leads to solving the murder of 21-year-old Josh Warneke, who was bashed as he walked home from a night out in Broome seven years ago.
Mr Warneke's body was found on the side of Old Broome Road on February 26, 2010.
Aboriginal man Gene Gibson, who is from the remote desert community of Kiwirrkurra and is cognitively impaired, had pleaded guilty to manslaughter and was sentenced to seven-and-a-half years in prison, but had his conviction overturned in April.
A fresh murder probe was launched, and on Monday, Police Minister Michelle Roberts said cabinet had approved increasing the reward from $100,000 following a request from police.
It is available for information that leads to a conviction, and the state government might consider recommending a pardon for an informant provided they were not directly responsible for Mr Warneke's death.
"We're prepared to do whatever we can to assist police in solving this murder," Ms Roberts told reporters.
Police Commissioner Karl O'Callaghan said it was always difficult to solve cold cases and detectives were dealing with some "very vulnerable" witnesses.
"It's a complex investigation dealing with a lot of people who may be witnesses who don't have English as a prime language."
Acting Detective Superintendent Pete Branchi said a mobile police facility would be set up at several locations in Broome over the next week in the hope someone might come forward with information.
"We believe there are people in the community who know what happened to Josh but for their own reasons have not yet spoken up," he said.
Det Supt Branchi said given the passage of time, there might be changes in allegiances and circumstances.
"They may have felt scared or intimidated about talking to police in 2010, or there may have been some strong, albeit misguided, loyalty to the murderer."
Police also want a woman who called Crime Stoppers on June 9 to come forward.
Ms Roberts said she was unaware of any compensation claim for Mr Gibson, who is yet to meet with Mr O'Callaghan.