Kathleen Mary Severino, 70, was savagely bashed in her Drummond Street South home on December 31, 1987. Her body was discovered by her daughter Glenda and son-in-law Ron when they called to the house for lunch on New Year's Day.

Announcing a $1 million reward in exchange for information leading to the arrest and conviction of those responsible for the murder on Wednesday, Detective Inspector Andrew Stamper told reporters he "absolutely believed" the case was solvable.

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He said police believed Mrs Severino's murder was the result of "a burglary gone wrong".

Investigators believe Mrs Severino was murdered between 10.30 and 11.30pm that New Year's Eve.

A male and female were spotted in the vicinity of Mrs Severino's house around that time and Detective Inspector Stamper said it had long been believed this sighting was linked to the crime.

Earlier this week: 'Hell on earth': daughter pleads for answers on horrific cold case murder

While a person charged in 1990 resembled the description of that male, he said it could be possible that it was not linked.

A 19-year-old male, Craig Edward Meizys, was charged with Mrs Severino's murder in July 1990. However, the charges were dropped when a key witness retracted their evidence.

Mrs Severino's daughter, Glenda, said the witnesses had allegedly been threatened and "turned" against the prosecution.

Meizys died as a result of a medical incident in 2017.

Detective Inspector Stamper said that despite this charge, detectives were still investigating different possibilities as to who murdered Mrs Severino.

A forensic examination of the home at the time could not determine how many people were involved.

Detective Inspector Stamper said there was a possibility that more than one person was involved in the burglary and or the subsequent murder, or who simply knew what had happened.

While they have people of interest, they are also keeping an open mind.

"Notwithstanding the fact that somebody who was charged with this crime is now deceased, we firmly believe that there are other people in the community who were potentially involved or certainly know what happened on that night."

He appealed to these people, or the female seen in the Drummond Street area around that time, to come forward to help police solve the "absolutely horrendous" crime.

He added that indemnity from prosecution was something which could be considered down that track.

While many years have passed, he said he was sure the people who knew about it would not have forgotten as it was such a horrific crime.

"Someone may have kept a secret for 33 years under a fear that they will be charged but now is the time to come forward," he added.

Glenda has lived with the trauma of her mother's murder and nobody being held responsible for more than three decades and simply wants answers.

"A person should be safe in their own home, in their own locked house, in their bed asleep. They should be left alone but somehow some greedy, selfish person has decided they want something but she had nothing. There was nothing there for them to take."

Adding that she can't understand why somebody would hurt her mother, she said she was no threat and the burglar could have simply walked out of the house.

Instead, they "viciously bashed" her mother and it is something she can't forgive.

Detailing how the murder had broken her family, describing the years since as like "hell", she pleaded for anyone with any information, even if they have detailed it to police before, to come forward again to help bring justice for her much-loved mother.

Glenda said withholding information about a murder which had so terribly affected a family was "cruel".

"I believe there are people alive that know something. There are people out there that know something. How they can live with themselves? I don't know. Probably because they didn't know her and that makes it easier for them."

She said someone coming forward would mean her mum could finally be at peace and then so could her family.

Glenda said she hoped the $1 million reward would encourage somebody to come forward, as it could change their life as well.

"They will have money to do whatever they need to do or get away.

"For us, there are no winners but for someone to come in and collect that reward will put mum at rest. It's all about mum - we need mum to be at peace.

"We hope that somebody who has a heart will come forward and give us the answers we need. This investigation is definitely solvable but it's up to the people that know something to please come forward."

Anyone with information that could assist investigators is urged to contact Crime Stoppers on 1800 333 000 or submit a report online at www.crimestoppersvic.com.au