DNA advances are being used in a bid to solve a St Kilda rape case from 1987

Prosecutors have alleged DNA technology advances have helped solve a violent rape case from 1987.

Cold case alleged rapist Theodoros Tsalkos. Picture: Josie Hayden

Advances in DNA technology have helped police crack a 33-year-old schoolgirl rape case, prosecutors allege.

But lawyers for accused man Theodoros Tsalkos argue he is not the only DNA match in the case.

Mr Tsalkos, 59, faces 27 charges over the violent rape of two teenage girls in St Kilda in May 1987 while employed as a “sitter” at brothels in the area.

One of his alleged victims has since died but the woman’s daughter watched an online committal hearing in the Melbourne Magistrates’ Court on Monday.

Mr Tsalkos is fighting allegations he picked up the two girls and drove them to a dimly lit lane near Elwood canal where he subjected them to hours of sexual violence while threatening to kill them.

The girls, aged 15 and 16 at the time, had become street sex workers just four days earlier and police allege Mr Tsalkos, then 25, told them he was an undercover police officer.

“Well girls, you’ve been busted for prostitution,” he allegedly said before ordering one of the girls to undress.

When she refused, her attacker said “I could blow your brains out”, a summary released by the court states.

Mr Tsalkos allegedly raped one of the girls before driving to a public toilet and raping both teens and forcing them to perform sex acts on each other before dropping them back in St Kilda.

The girls allegedly “bolted” to a nearby friend’s house and immediately reported their ordeal to police.

They were taken to hospital and DNA swabs were taken and frozen. The case sat dormant for 25 years until forensic scientists began analysing hundreds of frozen samples linked to cold cases in 2012.

Forensic officer Kate Outteridge told a contested committal hearing on Monday she had spent four years working on the case.

Ms Outteridge said once Mr Tsalkos became a person of interest his DNA was compared with the samples taken from the two girls in 1987 and delivered a result that was “one hundred billion times” more likely to be a match than not.

She also gave evidence one of the DNA samples taken from one of the young girls matched another man, but said it was not her role to determine if someone committed an offence, rather it was to present her findings to detectives.

Defence lawyer Martin Kozlowski said it was “very much an identity case” and questioned Ms Outteridge on how DNA samples were stored and preserved over long periods.

Earlier on Monday, the surviving victim gave testimony in closed court.

The committal hearing continues and two retired police officers are expected to give evidence on Tuesday.