The preliminary hearing for two Watson Lake RCMP officers charged with sexual assault began Tuesday in Whitehorse.

Graham Belak and Shawn McLaughlin are both charged with sexually assaulting a woman in the Yukon-B.C. border town on the same day in March. Both men were off-duty at the time of the alleged offence.

They were formally charged with the crime on March 8, a day after the accusation was made.

Crown prosecutor Robert Beck called four witnesses Tuesday; the alleged victim, one of her colleagues and two men who socialized with the accused officers on the night in question.

All of the evidence given at the preliminary hearing is barred from publication. At the end of the hearing - which is scheduled to end today - visiting judge Mike Hubbard will decide if there is enough evidence to warrant a trial.

Once charges were laid in the spring, the two officers were suspended from duty, with pay. They both promptly left the town of Watson Lake, situated on the Alaska Highway near the Yukon-B.C. border.

After initial inquiries were made by the local Mounties, the Edmonton city police force was called in to take over the investigation.

Beck was also brought in from Alberta to prosecute the men, as the Yukon-based federal prosecutors would have worked closely with both men in their capacity as police officers.

McLaughlin, 32, is married with children. Belak is single and comes from North Battleford, Sask.

Before becoming a police officer, the 29-year-old man was a top-level hockey player, drafted by the Colorado Avalanche in 1997.

Belak and McLaughlin appeared in court Tuesday for the first time since the charges were laid against them, accompanied by their Toronto-based lawyers, Robert Warren and Andrew McKay.