Sacha Baron Cohen turned heads at the London premiere of "Grimsby" on Monday.

The 44-year-old actor walked the red carpet in a turtleneck and underwear as his character, Norman "Nobby" Grimsby. The movie will be released as "The Brothers Grimsby" in the U.S.

Cohen showed off his gold chain and leather gun holsters as he posed for photos with co-star Mark Strong, who plays Sebastian Grimsby. The actor was later joined by his wife, actress Isla Fisher, who portrays Margaret.

"The Transporter" director Louis Leterrier helmed the film, which opens Mar. 11 in the U.S. The movie marks Cohen's first major screen role since Thenardier in the 2012 adaptation of "Les Miserables" starring Hugh Jackman.

"The Brothers Grimsby" follows Nobby, a dim-witted football fanatic, and his long-lost brother Sebastian, a black-ops spy, as they team up to save the world. Rebel Wilson, Penelope Cruz, Gabourey Sidibe and Annabelle Wallis co-star.

"It's the story of two brothers who were orphaned at the age of six," Cohen revealed in an interview with BBC Radio 1 on Monday.

"One of them went to a posh family in London -- Eaton, Cambridge, MI6 -- the other one just stayed in the Grimsby foster system."

Cohen is known for Channel 4/HBO series "Da Ali G Show" and starred in the feature films "Borat," "Bruno" and "The Dictator." He also voices King Julien in the "Madagascar" movies and will play Time in "Alice Through the Looking Glass."