New evidence obtained by the prosecution in the Claremont serial killer case threatens to further delay the trial of accused man Bradley Edwards.

Key points: Pieces of Telstra clothing used in the 1990s have been handed to prosecutors

Pieces of Telstra clothing used in the 1990s have been handed to prosecutors It will require forensic testing which may push back the trial's July 22 start date

It will require forensic testing which may push back the trial's July 22 start date Mr Edwards is accused of killing Sarah Spiers, Jane Rimmer and Ciara Glennon

A case management hearing was held today ahead of the trial, which is scheduled to begin on July 22.

Mr Edwards, 50, is accused of murdering Sarah Spiers, Jane Rimmer and Ciara Glennon, who all vanished from the Claremont night precinct in the mid-1990s.

He is also accused of sexually motivated attacks on two other women, one in 1988 and another in 1995.

He denies all the allegations against him.

Today prosecutor Carmel Barbagallo told the court new pieces of clothing had been obtained by police that required forensic testing.

She said the items were provided by a Telstra employee who had worked for the company in the 1990s, and the clothing was "utilised by technicians at the time".

Mr Edwards worked as a Telstra technician at the time of the killings and drove a work-issued car.

Evidence potentially 'quite significant'

The court heard the prosecution planned to compare fibres from the clothing with fibres found on other materials.

However, that testing and a subsequent ChemCentre report was unlikely to be complete before the end of June — allowing little time for the material to be disclosed to, and considered by, the defence team ahead of the trial start date.

Justice Stephen Hall questioned the timing of that report and whether delaying the trial would lead to even more new evidence coming to light.

Bradley Edwards is accused of killing (from top) Sarah Spiers, Jane Rimmer and Ciara Glennon. ( ABC News )

"This is going to potentially imperil the start of the trial," Justice Hall said.

"Every time there is a shift in dates there's a risk that other inquiries will be pursued."

Ms Barbagallo said staff were progressing as quickly as possible, while ensuring the accuracy of their work.

"Those working on this are acutely aware of the urgency of it," she said.

"The potential of this evidence, we say, is quite significant.

"We're prepared to draw a line in the sand but this evidence falls to this side of that."

Victim's family accepting of possible delay

Defence lawyer Paul Yovich suggested such a report would take his team eight to 12 weeks to review.

He said he was eager to see the trial start on time but also wanted to ensure the state's case was fully disclosed.

Justice Hall did not amend the July 22 start date today, but acknowledged it was subject to change.

Both Don Spiers, the father of Sarah, and Denis Glennon, Ciara's father, were in court.

Denis Glennon and Don Spiers both attended the hearing. ( ABC News: Hugh Sando )

As he left the building, Mr Spiers was asked whether he was frustrated by the prospect of a further delay.

"That's the process and that's to be accepted," he said.

The timing will be discussed further at a pre trial hearing scheduled for June 18.