Officials of Ashbury College, above, deny allegations that teachers inappropriately handled a student's sexual assault complaint. (CBC)

Ottawa's Ashbury College says its teachers responded in a timely and appropriate manner to an alleged assault on a school trip three years ago.

Three students of the private school, as well as the school's headmaster and four teachers, were named in a lawsuit filed by a 16-year-old boy and his parents in November 2009.

The lawsuit states that in 2007, two students allegedly pinned the youth to his bed, while another sexually assaulted him and a fourth allegedly videotaped the attack while on a school trip in Boston, Mass.

No further details of the alleged assault have been released.

A statement of defence filed in Ontario's Superior Court of Justice by the school Friday afternoon defends its teachers, saying they handled the incident in a professional manner, co-operating fully with police.

The youth and his parents claim the school did not deal with the victim appropriately and responded out of self-interest by not contacting Boston police immediately.

Teachers at the time of the incident seized the video equipment, spoke to the alleged attackers and sent two of them home after speaking to headmaster Tam Matthews, said the defence statement, according to the Ottawa Citizen.

Two of the accused students are facing indecent assault and battery charges by Massachusetts authorities.

Matthews told CBC News in November that all the students involved were boys who went to the boarding and day school, which is coed for Grades 9 to 12.

Ashbury College is a private boarding and day school founded in 1891.