The company that makes Carling beer is being sued for more than £7m in a legal row over a novelty drinking game for Apple's iPhone.
US software developer Hottrix alleges that American brewers Molson Coors copied an application called iBeer available through Apple's online store.
The $3 (£1.73) joke game turns the phone into a virtual beer glass.
Users can swill the liquid around by moving the handset and pretend to drink by tipping it back.
The 12-page lawsuit filed in Las Vegas alleges that Carling's advertising agency tried to license iBeer for "marketing purposes".
When Hottrix refused, it is claimed the company copied the idea and built it into a free download called iPint.
In court documents, Hottrix accuses Molson Coors of causing "irreparable damage and lost profits".
The lawsuit goes on to say: "As iPint increased in popularity, iBeer decreased in popularity since end-users could get ostensibly the same application without a direct cost (besides viewing the Carling advertising) of paying $2.99 (£1.73) for iBeer."
iPint also comes with a second game which allows users to control a drink as it slides along a bar.
Hottrix claims the game was bundled with iPint to "create a false distinction between the infringing app and the iBeer content".
The company complained to Apple, which has removed iPint from the US version of its application store but the game is still available in the UK and other international markets.
In a statement Molson Coors said: "We are confident that we've handled this matter appropriately, and will vigorously defend the action."