La Rochelle: Male students and staff at a French school have begun providing police with DNA samples in an unprecedented operation to discover who raped a 16-year-old pupil.

The operation has raised concerns over rights violations after the prosecutor handling the case said anyone refusing to submit a sample would be considered a potential suspect.

By mid-afternoon on Monday 142 of the 527 boys or men who have been asked to participate had provided samples at Fenelon-Notre Dame, a private Catholic high school in the port city of La Rochelle.

"Nobody has objected and the samples have been taken in a calm and orderly fashion," local prosecutor Isabelle Pagenelle told reporters, defending her decision to order the tests.