A cold case review of a high-profile missing person investigation led to the discovery of the alleged murder of another woman, who was never reported as missing, the WA Supreme Court has heard.

Key points: Chris Blennerhassett is on trial accused of murdering Rebecca Delalande

Chris Blennerhassett is on trial accused of murdering Rebecca Delalande Her alleged murder came to light during a review into Lisa Brown's disappearance

Her alleged murder came to light during a review into Lisa Brown's disappearance The two women were known to each other, WA's Supreme Court has heard

The revelation came at the start of the trial of Chris Blennerhassett, 46, who is accused of fatally assaulting 23-year-old Rebecca Delalande at a house in Armadale in November 2001.

Prosecutor Ben Stanwix said police only "happened upon" the disappearance of Ms Delalande during a 2017 review of the investigation into the disappearance of 19-year-old Lisa Brown.

Ms Brown was last seen in the inner-Perth suburb of Highgate early on November 10, 1998.

Mr Stanwix said that during the review, Ms Delalande's name came up as someone who knew Ms Brown and who had previously provided information to the police about her.

He said the officers wanted to speak to Ms Delalande again but could not find any trace of her, so then began investigating what happened to her.

'Woman's limp body carried to car': Witness

Mr Stanwix said Mr Blennerhasset was then identified as someone Ms Delalande was having a relationship with at the time.

He said it was alleged that during an argument in a bedroom of the share house where they were living, Mr Blennerhassett had struck Ms Delalande to the head and then disposed of her body "in a way that it can never be found".

Lisa Brown was 19 when she disappeared in 1998. ( Supplied: missingpersons.gov.au )

The court heard the witnesses at the trial would include a housemate of Mr Blennerhassett who claims that after hearing the pair argue, he saw Mr Blennerhasset carry Ms Delalande's limp body to his car before driving off.

Mr Stanwix said the witness would testify that Mr Blennerhassett later told him he had "headbutted" Ms Delalande and she was dead.

Mr Blennerhassett is also alleged to have said he burnt her body in a 44-gallon drum, which it is alleged was "most likely" done at a Bayswater factory unit owned by his father.

Mr Stanwix said while the state could not say exactly how Ms Delalande's remains were disposed of, there were usually drums of nitric acid at the factory in which human tissue could be "digested", especially if they had already been burnt.

Police conducted a detailed search of the premises including the use of ground-probing equipment but nothing was found.

Former 'street kid' never reported missing

The court heard Ms Delalande had never been reported missing and because of a violent home life, she had become "a street kid" from a young age.

Mr Stanwix described her lifestyle as chaotic and itinerant, saying she had no permanent home, an entrenched heroin addiction and had worked as a sex worker.

Police believe Ms Delalande's remains were disposed of at a factory unit in Bayswater. ( ABC News: Herlyn Kaur )

He said Ms Delalande did have contact with some members of her family but her mother, who had another much younger child, had been forced to make "a terrible choice" between keeping the door open for her troubled daughter or protecting her baby from the lifestyle her daughter was leading.

The court was told the investigation into Ms Delalande's disappearance involved looking back at records such as her contact with police, her banking transactions, her Centrelink details and medical and dental appointments she had.

However, Mr Stanwix said their activity ceased in November 2001 with the exception of a train infringement in 2003, which he said appeared to be a case of someone giving a false name.

The trial is set down for two weeks.