(Cover) - EN Showbiz - Jack Nicholson surprised Leonardo DiCaprio by pulling a weapon on him while shooting The Departed.

Jack and Leonardo both starred in the hit 2006 crime drama directed by iconic moviemaker Martin Scorsese, with Martin revealing some interesting stories about the stars from on-set.

Apparently the team struggled to get things right during the shooting of one pivotal scene in the film, so Jack unexpectedly pulled a gun on Leonardo to make it edgier.

"The first thing Jack did was sniff the glass and say, 'I smell a rat'... And then he pulled a gun on him," recalled Martin in an interview with Richard Schickel for his imminent book, Conversations With Scorsese.

Martin had been just as surprised as Leonardo by Jacks actions, and he was thrilled with the footage created as a result. The director was especially pleased with the shock on Leonardos face, which made the final cut of the movie.

"He didn't tell me he had a gun. It was great... we took a lot out, but Leo's reaction is real-time," added Martin.

The Departed tells the story of two men working undercover within the Massachusetts State Police and the Irish mafia, and is often cited as one of the greatest films ever made. (C) Cover Media