Canada's Prime Minister Justin Trudeau (Photo: AP)

Canada's Prime Minister Justin Trudeau, a fervent advocate of the multiculturalism integral to Canadian identity, wore brownface makeup to a party at a school where he taught 18 years ago, Time magazine reported Wednesday.

The report comes a week into a federal election campaign with Trudeau's Liberal Party in a tight contest against the Conservatives led by Andrew Scheer.

Trudeau, 47, whose party won a landslide victory in 2015, has already been under attack for an ethics lapse and other controversies.

US-based Time published a photograph, which AFP has not independently verified, that it said showed Trudeau, then 29, wearing a turban and robes with his face, neck and hands darkened at an "Arabian Nights" gala in 2001.

The picture appears in the 2000-2001 yearbook of West Point Grey Academy, a private school where Trudeau taught at the time, the magazine said.

It cited Zita Astravas, of the Liberal Party's  media relations division, as confirming Trudeau was in the photo "at the school's annual dinner which had a costume theme of 'Arabian Nights.'"

Politicians in Canada's southern neighbor the United States, with its history of slavery and segregation, have been embroiled in scandal this year over their alleged wearing of "blackface."

Virginia Governor Ralph Northam refused to resign after first admitting he appeared in a yearbook photograph showing a person in blackface and another wearing Ku Klux Klan robes, only to deny a day later that either individual was him.

Half of Trudeau's cabinet are women, and at least six members have Asian or African heritage.

Accusations of political meddling in a bribery case against engineering giant SNC-Lavalin plunged support for Trudeau at the beginning of the year.

The scandal broke when two members of his own cabinet accused him and his aides of meddling in the prosecution of SNC-Lavalin to save jobs.

Both the ministers were women and one was Canada's first indigenous attorney general. They were expelled from the party.

The episode cost Trudeau support among women, indigenous people and young people -- constituents that helped propel him to victory in 2015.

Trudeau is the son of former prime minister Pierre Trudeau, who is considered the father of modern Canada.

The younger Trudeau's stint as a teacher belonged to a colorful past that also included working as a snowboard instructor, a bartender and a bouncer.