York Regional Police say a vice-principal at a high school in Markham was arrested Tuesday after allegedly sexually assaulting a former student last year.

The vice-principal works at St. Robert Catholic High School on Leslie Street in Markham.

Const. Andy Pattenden said the matter involves a 17-year-old former student, and the assault allegedly took place in July 2015. Investigators say they became aware of the allegation on March 16. The victim’s identity is covered by a publication ban.

Board communications manager Sonia Gallo said the board “takes this matter very seriously,” and has dispatched support staff including counsellors and psychologists to the school to assist staff and students.

A letter was sent home with all students of the school on Tuesday. In it, the board urges parents and students “to respect the privacy of the individuals involved in this situation, and not to engage in speculation.”

The letter did not state the nature of the allegations made against the vice principal. Gallo would not disclose the allegations made against him, citing privacy concerns.

Paul Paterson, 40, was arrested without incident on Tuesday, police said.

He faces one count of sexual assault and one count of sexual exploitation.

Gallo said Paterson is on leave with pay, in line with board policy for employees.

Paterson appeared in court in Newmarket on Wednesday for a bail hearing.