A $250,000 reward has been offered in a bid to solve a two-decade-old murder in Western Australia and people who come forward may be granted immunity from prosecution.
In March 1999, Andrew Podpinka was found stabbed to death in his home in Morley in Perth's north-eastern suburbs by his wife and daughter when they returned from shopping.
The 43-year-old was found in the master bedroom with extensive wounds to his chest and back.
"This was a brutal killing of a man who was attacked while sitting inside his own home," Police Minister Paul Papalia said on Wednesday.
"Investigators are confident someone in the community knows what happened that day.
"I hope this reward might prompt someone to come forward and give information to detectives.
"For the sake of Mr Podpinka's family, who have suffered pain and anguish for more than 20 years, I urge you to speak up."
Mr Papalia said authorities might be prepared to consider protection from prosecution or pardon for anyone with information that leads to the conviction of the person or persons responsible for Mr Podpinka's murder.
This was on the provision that the informant was not directly responsible for the killing.
Police Assistant Commissioner Brad Royce said the investigation into the killing of Mr Podpinka had always remained active.
"We don't put files away. We continue," he said.
"We're at that space now where we've exhausted the opportunities we had from the original scene.
"Now we're asking people who may know something to come forward and help us and help the Podpinka family."
Mr Royce said developments in forensic technology had advanced the investigation but more information was required.
Mr Podpinka was a slight man with some physical disabilities and would not have been able to fight off an attacker.
Mr Papalia said bringing someone to justice would be "incredibly valuable" to his family.
He said the reward was approved by state cabinet after a recommendation from police.
