A couple celebrity blogs are reporting that security has been tightened around the set of The Fighter after an intruder got too close to Oscar nominee Amy Adams.

Hours after more than 1,000 extras had taken part in a scene for the boxing flick at the Tsongas Arena the actress, who plays Mark Wahlberg's girlfriend Charlene in the film, was left "startled" when a man climbed the stairs of her trailer and peeked inside just after she had wrapped filming late on Thursday night.

"Amy was getting ready to leave the set when the guy climbed the steps right outside her trailer and said: 'I'm looking for my cousin.' an insider told Radar Online.com. "Amy, who was fully dressed and was with a production worker, yelled out: 'What the hell are you doing?' and the guy quickly climbed down the stairs before running off."

"She was totally unharmed and a number plate was passed onto the police from a car which we think he escaped in." the insider added.

"The guy in question was pretty young maybe in his late teens or early twenties and it is not known why he was in this particular area."