Investigators hunt for new leads in 'brutal' 40-year-old sexual assault case

Police are using DNA technology and new information to find the man behind two "brutal attacks" on 82-year-old Jessie Grace Lauder in Newport, Melbourne between 1981 and 1983.

Investigators believe the attacker lived near Mrs Lauder's Mason Street home during the two-year period after an appeal for information in 2016 and an offer of a $500,000 reward returned promising new leads.

"We are particularly keen to hear from anyone who can remember a man matching that description who might have lived on the surrounding streets - Mason, Johnston, Oxford and Lucius and Cunningham lanes," Detective Inspector Mark Burnett said.

"Though Jessie is sadly no longer alive, these brutal attacks have had enduring effects on her family. Jessie was a vulnerable older woman who should have been safe in her own home," he said.

"On the other hand, this man has lived these last 40 years with relative freedom and no repercussions yet for what he did."

Mrs Lauder, who was widowed in 1977 and died in 1993, lived in her home in Melbourne's inner southwest for 55 years.

On the night of September 22, 1981, a man forced entry to her house through the back door around 10pm.

The attacker, armed with a knife, confronted Mrs Lauder in her bedroom, took her to another room in the house and sexually assaulted her, police said.

The man allegedly rifled through Mrs Lauder's purse before fleeing over the back fence into a vacant lot on Oxford Street.

The attacker returned two years later on July 6, 1983, when Mrs Lauder was getting ready for bed, police said.

This time the man allegedly forced entry through the front door, checked the home for other people and sexually assaulted the victim in the loungeroom.

"During the second incident the man made reference to the earlier offence and warned Jessie not to call police," investigators said.

Police believe the man wore gloves, a beanie, work boots and items to conceal his face during the attacks.

At the time, he was described as a man aged between 20 and 30 years old with a fair complexion, dark hair, 175 centimetres tall and he spoke with an Australian accent.

"It is as important as ever that the person responsible is brought to justice and I absolutely believe that with the right information, it can be solved," Detective Inspector Burnett said.

"Historical investigations are unique in that updates to science, methodology and legislation allow us to progress a case in a way that may not have been possible at the time of the incident, so receiving information even over 40 years later can still make an enormous difference."

Investigators believe the attacker will be known to people who lived in the area at the time.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or make a confidential report at www.crimestoppersvic.com.au