ST. JEROME - The judge presiding over a sexual assault case involving a high school teacher and one of her students suddenly stepped down on Monday.

Justice Francois Beaudoin said that he could no longer continue overseeing the case of Tania Pontbriand because of personal reasons, but did not elaborate.

A new judge will have to be appointed on Tuesday, but it's anybody's guess as to what will happen next.

The new judge will have two choices: either continue where Beaudoin left off, relying on court stenography to get up to speed, or to decide the case must begin again from the beginning.

Pontbriand, 41, is accused of sexually assaulting a student during a relationship that began when she was 32 years old, and the boy was just 15.

The student testified in court that the relationship lasted two years, after which he was depressed and suicidal, and after seeking counselling he went to police.

The boy, now in his twenties, was confident when testifying in August, and this week was supposed to undergo cross-examination from defence lawyers.

Pontbriand had attempted to get the trial thrown out on the basis that the accusations date from 2002 to 2004 and therefore violate her right to a speedy trial but the judge refused to accommodate her demand.

Pontbriand, a former teacher at the Sir Wilfrid Laurier school board, faces a maximum of 10 years in prison on sexual assault charges due to the position of authority she had over the boy.