TORONTO - Ontario's top court has ruled a once-respected choreographer who worked with top stars and the Toronto Blue Jays' dance troupes will have his name added to the national sex offender registry.

In 2007, Sean Debidin's trial on several sex charges involving a 15-year-old girl ended abruptly when he entered a guilty plea.

Although prosecutors asked that Debidin's name be added to the sex offender registry, the trial judge did not grant the order.

On Monday, Ontario's highest court overturned that decision.

The Ontario Court of Appeal has ordered that Debidin's name be placed on the list for 20 years.

Debidin admitted he repeatedly engaged in various sex acts with the girl between July 2003 and May 2004, when the 15-year-old was a member of one of the baseball team's dance troupes.

"I am satisfied that the trial judge's refusal to direct (sex offender) registration reflects error and cannot stand," a three-judge panel wrote in the decision released Monday.

"The restrictions (of being on the registry) are modest and do not prohibit the respondent from going anywhere, or doing anything."

Debidin, who was in his 40s at the time of the offences, also pleaded guilty to making child pornography because he videotaped himself and the girl having sex.

He was ultimately sentenced to four months.

In an affidavit, Debidin said he had worked with Shania Twain and Alanis Morissette and had choreographed the Juno Awards.

Sex between an adult and a child aged 14 or over is legal, but not when the adult is in a position of trust or authority over the teen, as Debidin was.

The victim's parents trusted him so much that they allowed the girl to stay, on occasion, at his west Toronto home.