The Ontario coroner's office has shut down an inquest into the death of Ashley Smith, the New Brunswick teenager who asphyxiated herself in an Ontario prison cell while guards watched.

A new inquest will be launched from scratch, the office said Friday.

Smith, who was 19, strangled herself with a piece of cloth in 2007 at the Grand Valley Institution for Women, a federal prison in Kitchener.

On Friday in Toronto, the coroner cited numerous legal challenges as one of the reasons for stopping the much delayed inquest, which began in May under Dr. Bonita Porter.

While the inquest was adjourned over the summer, Porter was taken off the case, apparently because the proceeding couldn't be completed before her retirement date.

The inquest resumed in September under Dr. John Carlisle but was adjourned again when Carlisle's jurisdiction was challenged by the lawyer for the Smith family.

Family's lawyer wanted fresh start

Julian Falconer argued the inquest should have started fresh under Carlisle instead of picking up where Porter left off.

In his ruling Friday, Carlisle said that if the inquest continued, he would have to deal with evidence already heard by Porter, and the process of getting to know the old material could be time-consuming and cause further delays. These delays wouldn't be necessary, however, if the inquest started over, and it's even possible some of the contentious issues of the first inquest effort could be avoided, he said.

Carlisle also said there had been a break of four and a half months between sittings for the jurors, who, if the same inquest continued, would need refreshing on the evidence, which would also mean delays.

The coroner dismissed the jury and said different jurors will be chosen for the new inquest.