'RocknRolla' director Guy Ritchie has been threatened by a crazed Madonna fan who was wielding a knife and burst onto the set of his new movie 'Sherlock Holmes'.

The British director - who split from the 50-year-old singer earlier this month after nearly eight years of marriage - was filming his new movie 'Sherlock Holmes' in Manchester, England when a 16-year-old boy burst onto the set and threatened to kill him.

The Sunday Mirror reports that Guy, 40, was standing just feet away from the teenager, who was brandishing a 12-inch knife, when he began shouting: "Where's Guy? I am going to kill him! I'm Madonna's biggest fan! I'm going to kill Guy."

Security guards quickly stepped in to protect Guy and managed to wrestle the youth - dressed entirely in black - to the ground.