Vince Vaughn, the US actor dating former Friends star Jennifer Aniston, is to sue two UK newspapers.
The couple have been the subject of intense media scrutiny
He is taking legal action against the Sun, Daily Mirror and New York Post after they said he kissed a "mystery woman" at a London charity event.
The papers reported that Mr Vaughn and Ms Aniston had broken up days before.
The couple say they remain together. Mr Vaughn is due to argue that the articles falsely suggested he had been unfaithful to Ms Aniston.
The Sun and Daily Mirror articles were accompanied by a photograph, which Mr Vaughn will argue was seriously misleading.
He will argue that the suggestion he was involved in a passionate embrace and kiss was false, said a statement from the London lawyers Schillings, who are representing the actor.
The alleged incident took place at the Old Vic theatre earlier this month.
Mr Vaughn and Ms Aniston reportedly started dating during the filming of their recent romantic comedy, The Break-Up.