LOS ANGELES – “One Night in Paris,” the sex tape that launched a tabloid obsession over hotel heiress Paris Hilton, may not rank among the actress’s favorite screen roles, but it’s still a hot choice among adult entertainment connoisseurs.

The DVD has sold 600,000 copies since Hilton’s ex-boyfriend Richard Salomon took it to market in 2004, winning an Adult Video News Award for 2005’s Best Selling Title.

Hilton would never settle for counterfeit anything, so why should her fans?

On Monday, the authorized Internet purveyor of the Hilton sex tape launched a legal missive against Web sites that are selling the film unauthorized and luring customers into paying subscription fees with the false promise of a peek at the video.

Delaware-based XPays Inc., which owns the rights to online distribution of “One Night in Paris,” filed suit Sept. 11 in Los Angeles Superior Court against seven Internet companies, alleging copyright infringement, false designation or representation, unfair competition and, in one case, libel.

Two Internet companies based in Illinois and Arizona and five international companies from the Netherlands, Spain, Australia, Singapore and Denmark are named as defendants.

Hilton and Salomon are not plaintiffs in the suit, but a similar suit was filed in 2004 by Salomon against Web site owners who were trying to cash in on the video’s popularity.

XPays is seeking damages in excess of $1 million, and an injunction preventing the sites from further use of the material.

“With its unprecedented success, the video has also become one of the most illegally copied and exploited properties on the Internet,” the suit states.

“Driven by sheer greed the defendants have unlawfully posted images from the video to secure paid subscriptions to their Web sites, have compensated popular search engines such as Google and Yahoo to direct those searching for the video to their sites, have undercut XPays by offering the video for lower prices, and/or have profited from their affiliates who have been outwardly engaging in the same unlawful misconduct,” the suit alleges.

An attorney for XPays says more lawsuits may be on the way.

“XPays intends to aggressively enforce its rights in the Paris Hilton sex video, and will continue seeking out those who are blatantly infringing upon those rights,” attorney Paul Berra told CourtTVnews.com.

Hilton initially fought the release of the tape when it first surfaced in 2003, but later acquiesced after negotiations with Salomon’s attorneys.

In January 2004, Salomon obtained the exclusive copyrights and other rights to sell and exploit the 37-minute-long video featuring the couple’s mating habits, which he directed in a Las Vegas hotel room.

Red Light District Video now has the DVD distribution rights and XPays has the rights to online sales.

Berra won’t comment on the potential losses sustained by XPays, or what Hilton and Salomon make from the tape. A Hilton attorney confirmed last year to The New York Times that she makes a profit from it. Hilton’s publicist was not immediately available for comment.