Hollywood studio Warner Bros. Pictures is cancelling promotional previews of its movies in Canada, citing rampant, unauthorized pirating of new releases north of the border.

The studio will immediately stop all "promotional and word-of-mouth screenings" of new releases, starting with Ocean's Thirteen and including the much-anticipated Harry Potter and the Order of the Phoenix.

"We regret having to cancel our screenings in Canada, but our studio must take steps to protect not only our branded assets but our commitment to our filmmakers and to our distributors," Dan Fellman, the studio's president of domestic distribution, said in a release.

Warner Bros. and the other major Hollywood studios have been calling on the Canadian government to take a harder line on those caught illicitly filming new releases for pirating worldwide.

"We have a serious issue that the industry is trying to address," Darcy Antonellis, Warner's senior vice-president of worldwide anti-piracy operations, told CBC News on Tuesday afternoon.

Antonellis suggested that Canada could benefit from legislation similar to that enacted in the U.S. in 2005 that made it a felony for an audience member to illicitly film a movie inside a theatre.

"It's proven quite effective," she said.

She also specified that the cancelled screenings do not affect the usual advance press or critics' screenings held in advance of a new movie's release.

In February, the U.S. International Intellectual Property Alliance put Canada on a watchlist of countries it believes responsible for illegal filming and copying of movies. The group alleged that the recording, movie and software industries lose $225 million a year due to illegal trafficking in Canada.