Angelina Jolie to adopt a baby from Burma

According to the source, Angelina's frustration at not doing enough to help the Third World is exacerbated by her sense that she and Pitt spend too much time in Hollywood.

She is also said to have become depressed after the death of her mother, French actress Marcheline Bertrand, in January. The actress has blamed her weight plummeting to under 7st on her grief.

Angelina has spoken in the past of her desire to start a "rainbow" family of children adopted from nations all over the world.

She recently said: "Ever since I was about 12, I've always wanted to adopt – I don't know why. We want to have a big, big family."