A Perth judge has ruled a Muslim woman cannot wear her traditional face covering while giving evidence in a fraud trial.

The 36-year-old woman, who is known only as Tasnim, had wanted to wear the niqab in court because there would be men there who were not her blood relations.

Tasnim has worn a burka, including a niqab which covers her face, all her adult life.

She has been living in Australia for seven years and wore the niqab at her citizenship ceremony.

She has lifted the niqab for passport checks at the airport, for her driver's licence photo and for medical and dental treatment.

Tasnim does not wear it at home if only direct family members are present.

She is giving evidence at the fraud trial of Anwar Sayed, the head of an Islamic school.

However, defence lawyers raised concerns that the jury members would not be able to properly assess her evidence.

In her ruling, District Court judge Shauna Deane said the court had not been able to find a similar case in Australia.

She said she did not consider it appropriate for Tasnim to wear a niqab in the dock.

She ruled Tasnim should give evidence with her face uncovered because the jury should not be impeded in its ability to assess her demeanour.

But the judge said her decision was in no way binding on any other court, as there was no reason for her to examine or discuss the Islamic religion, or to determine the practice of wearing certain garments.

Death threats

Sayed is accused of overstating student numbers at his school in order to claim government funds.

Earlier this month, defence lawyer Mark Trowell told the court Sayed had been "brutally stabbed in the chest and face".

It was later found that his injuries were much less serious.

But there has been speculation he was attacked over the niqab issue, as the court had already been told Sayed had received death threats.

Outside court today, Sayed's solicitor Swaran Ludher said it was a sensitive matter for some Muslims.

"The most important thing to stress is that Mr Sayed, the accused, did not raise this issue of whether a witness can wear a niqab or not wear a niqab," he said.

"He had no role in it to play, he has no problems with her wearing a niqab if she comes to court, that's her business. He has no objection to that."

In a statement, Tasnim said she accepted the judge's decision.

She said she never demanded to wear the niqab, she merely asked to dress as she normally would in front of people she does not know.

"I regret that this case has ignited the debate as to whether the burka should be banned in Australia," the statement said.

"This would be a step backwards for Australia and would only further widen the division between Muslim and non-Muslim Australians.

"I am a proud law-abiding Australian and I am not trying to change the Australian way of life. I am simply trying to live by my beliefs."

Sayed's trial is expected to be held in October.