The trial of three Tunisian policemen for raping a young woman last year, which sparked outrage when the prosecution tried to blame the victim, was adjourned Thursday until November 4.

The prosecutor asked for postponement because the alleged victim's medical report was still not ready, prompting condemnation from the defence lawyers.

The defence had asked for a doctor to conduct a psychiatric examination of the woman.

"It's not possible. We have been waiting (to make our case) since April 4," one of the policemen's lawyers, Sami Rebai, told the court.

But the judge insisted that the file, including the medical report, must be complete before the trial begins.

The woman's lawyers have also called for a postponement because the young woman has expressed her wish to attend but is now living in France, one of them, Bochra Belhaj Hmida, told AFP.

The three police officers are in custody awaiting trial, two of them on rape charges, with the third accused of extorting money from the woman's boyfriend.

The police say they took the couple by surprise as they were having sex in their car, in a suburb of Tunis, in September 2012.

Two of them then took the woman to a police car, where they raped her in turn, according to a judicial source, while a third allegedly restrained and tried to extort money from her fiance at a bank cashpoint.

The public prosecution tried unsuccessfully to bring indecency charges against the couple, which sparked a storm of protest in Tunisia and a campaign of support for the young woman.

She has since published a book in France giving her account of what happened, and entitled "Guilty of being raped."

The Islamist-led government was sharply criticised for its handling of the case, with the opposition accusing the ruling Ennahda party of trying to impose Islamic values on society, including by undermining the rights of women.