The man whose trial has led to controversy over the wearing of a Muslim headscarf in court has been "brutally stabbed" after being stopped in his car, his lawyer says.

Anwar Sayed, who a court yesterday heard had received written and verbal death threats for supposedly agitating to abolish the wearing of a niqab, also known as a burqa, was allegedly attacked this morning.

Mr Sayed is alleged to have obtained more than $750,000 from federal and state governments by artificially inflating student numbers at Muslim Ladies College in Kenwick.

But the case has been overshadowed by the niqab issue, which has raised legal questions on whether the witness should be entitled to obscure her face from the judge and jury.