A $1 million reward is on offer to help solve the cold case bashing murder of a Victorian grandmother during a "burglary gone wrong".
Kathleen Severino, 70, was found dead in the bedroom of her Ballarat home on January 1, 1988.
Police say she suffered fatal head injuries after being "savagely assaulted" sometime between 10.30 and 11.30pm on New Year's Eve.
A witness reported seeing a man and woman near Ms Severino's home at the time. The residence was ransacked but nothing was stolen.
Detective Inspector Andrew Stamper said on Wednesday he was the confident the murder was a "burglary gone wrong".
"In all probability she heard the burglary occurring and was ... subjected to a horrendous bashing," he told reporters.
"She disturbed someone in the house and as a result they've murdered her."
A 19-year-old man was arrested in 1990 but a murder charge against him was dropped after a witness revoked their evidence before trial.
The man died in 2017 and investigators say he remains a person of interest along with one of his former associates.
Ms Severino's daughter Glenda says she can never forgive her mother's killer.
"All I know is they've had 33 years of freedom and they shouldn't have," she told reporters.
"We've had 33 years of hell. It's still hard to believe that Mum's gone. She was much loved.
"It's broken us up as a family - she's missed out on so much in our family since she's been gone."
Insp Stamper says he's hopeful the $1 million offer will shed light on the case.
"We know people who commit or are part of horrific crimes such as these will often disclose their actions to someone," he said.
"Despite the decades that have passed there is every reason to believe someone out there today knows what happened to Kathleen and who is responsible."
He said while three decades had passed, it wasn't too late for her family to get justice.
"Police will not stop until we get closure for Kathleen's family, which can only be achieved by holding the individual or persons responsible for the brutal death of a much-loved grandmother to account," Insp Stamper said.
He added it was possible an indemnity would be considered for anyone who came forward with information.
© AAP 2021