The police complaint commissioner of B.C. has ordered an investigation into the conduct of one or more members of the Vancouver Police Department during an anti-pipeline protest on May 22.

The alleged incident took place outside a Liberal fundraiser at Vancouver's Opus Hotel, where Prime Minister Justin Trudeau was speaking.

In a statement, the police complaint commissioner says a video recorded during the anti-pipeline protest outside shows a woman approaching a man standing next to a uniformed police officer.

It says she appears to step forward and then falls to the ground after making contact with one of the men.

Following the video and reports in the media, commissioner Clayton Pecknold determined it was in the public interest to disclose that he has ordered an investigation into the alleged incident to determine whether it constitutes police misconduct.

During the prime minister's address at the hotel, an opponent of the Trans Mountain pipeline expansion from the Tsleil-Waututh Nation was ushered out of the fundraiser after interrupting Trudeau's remarks.