Brad Pitt and Angelina Jolie are "like prisoners" because of their fame.

The celebrity couple's friend and fellow A-list actor, Matt Damon, feels sorry for the fact even their everyday tasks are hard for them to accomplish in public without being scrutinised.

He told German TV station TELE 5: "I have friends who are like prisoners. Brad Pitt and Angelina Jolie, for instance.

"They can't just go someplace. If they go for a walk, it turns into an international incident.

"I'm really lucky, because I have the best of both worlds. I do the work that I love and need, but don't need paramilitary troops to protect me when I walk out my front door."

Oscar winner Matt, 40, is grateful of his low key life and that his wife, Luciana, and their four girls – Isabella, five, Gia, two, Stella, nine months and Alexia, Luciana's child from a previous marriage - don't get bothered too much in public.

'The Bourne Identity' star added: "I'm not as crazy as most of the other stars. I don't really know why, probably because I married a woman who isn't an actress. And we live in New York.

"As long as we don't show up in typical tourist spots, we can walk the streets without being noticed. New Yorkers are very cool, they don't flip out if they see me."