A Hollywood studio is to cancel all preview screenings of its movies in Canada, in an attempt to clamp down on "rampant" film piracy in the region.
Harry Potter and the Order of the Phoenix will not preview in Canada
Warner Bros will halt all "promotional and word-of-mouth screenings" of new releases, says the Hollywood Reporter.
The studio blamed the failure of the Canadian government to make camcording - videotaping a film directly off the cinema screen - an illegal practice.
The preview ban will affect Ocean's Thirteen and the latest Harry Potter.
"We regret having to cancel our screenings in Canada," said Dan Fellman, president of domestic distribution at Warner Brothers.
"But our studio must take steps to protect not only our branded assets, but our commitment to film-makers and to our distributors."
The ban was announced on Monday, as representatives from major film studios told a parliamentary committee in Canada that unauthorised recording of Hollywood films in domestic cinemas was rampant.
"Canada is the number one priority in terms of anti-camcording legislation," said Darcy Antonellis, a senior figure in worldwide anti-piracy operations at Warner Bros Entertainment.
"Within the first week of a film's release, you can almost be certain that somewhere out there a Canadian copy will show up."
Last year, Twentieth Century Fox threatened to postpone film releases in Canada to eliminate the threat of unauthorised camcording.
Meanwhile, the major studios are in talks with US cable company Comcast over plans to screen films on cable TV on the same day as they are released in cinemas.
Comcast's Stephen Burke told a trade show in Las Vegas that subscribers could be charged between $30 to $50 (£15-£25) to watch a film release at home on its opening day in cinemas.
"We've talked to the studios about this and they're all interested," said Mr Burke, but added that there were no imminent developments.
Studios, which make a large chunk of their profit from DVD sales, are eager to narrow the gap between big screen debuts and DVD releases, thereby reducing the need for a second promotional campaign.
However, cinema owners have strongly resisted any effort to close the window amid fears their attendances would fall.