Actor Simon Pegg, of Shaun Of The Dead and TV series Spaced, has been cast in Mission: Impossible 3, according to reports.
Tom Cruise has been in Rome to film scenes for the movie
He is to play an ally of Special Agent Ethan Hunt, played by Tom Cruise, the Hollywood Reporter said.
Pegg made his name in indie comedies on British TV, while his film credits also include The Reckoning and a cameo in Land of the Dead.
The Mission Impossible films are based on the hit 1960s and 1970s TV shows.
The third film, currently in production and being directed by Jeffrey Abrams, was put off for almost a year to allow Cruise time to find a new director and shoot War of the Worlds.
"I've been dying to work with Simon since I saw Shaun of the Dead. His comedic skill is remarkable. He's able to be hysterically funny while always seeming 100% real, even when he's killing zombies with vinyl records," Mr Abrams said.
The first movie in the Mission: Impossible series, directed by Brian de Palma in 1996, made $454m (£250m) worldwide.