Officials have said that a private prep school in Canada has ordered an investigation after four seniors were charged with sexually assaulting younger students.

The Winnipeg (Manitoba) Free Press reported on Sunday that a senior official of the University of Manitoba has been hired to conduct the external investigation at the elite St. John's-Ravenscourt School.

The newspaper also said that, four senior male students allegedly assaulted as many as 15 younger male boarding students, last fall and have been charged with sexual assault with a weapon, forcible confinement and uttering threats.

St. John's-Ravenscourt describes itself as an "independent, co-educational day and boarding university prep school."

The Free Press also said that David Morphy, U of M's vice provost of student affairs, began a special investigation at the Winnipeg school last week, including a review of the school's practices and policies, especially regarding its boarding school.

The final results of the investigation would be made public, Stephen Johnson, head of St. John's-Ravenscourt, said.

Johnson said, "This is what a great school does in a crisis. You don't try to bury it or hide it." (With Inputs from Agencies)