Police have made a fresh plea for information that could lead to a breakthrough in investigating the death of Canberra woman Irma Palasics 21 years ago.
In 1999, bandits broke into Ms Palasics' Canberra home, bound her, ransacked the place and beat the 72-year-old to death.
Her husband Gregor died a few years later never knowing his wife's killer.
On Friday, ACT police said new information suggested a person in Melbourne's Hungarian community had information on the murder.
Detective Sergeant Adam Rhynehart urged the person to speak to police.
"If you are a member of the Melbourne Hungarian community and have even the smallest piece of information that could assist in the ongoing investigation into the death of Irma Palasics we want to hear from you," he said.
"Your information could be what is needed to bring a person before the courts and provide the Palasics family the answers they've been searching for more than two decades."
A $500,000 reward is on offer for information leading to a successful prosecution.
In 2014, ACT police announced they had matched the killer's DNA to that of someone involved in an attempted robbery at a Canberra golf centre in 2010 and found they are related - possibly father and son.
The murderer was also believed to be behind two previous burglaries at the Palasics' homes in 1997 and 1998.