Bonham Carter announces pregnancy

A spokeswoman for the couple said they were "very happy", and the baby was due later this year.

The pair met while filming Planet Of The Apes in 2001, and had their first son, Billy, three years ago.

Bonham Carter, 41, who stars in the latest Harry Potter film, recently admitted she wanted another child, saying: "We've got to get on with it."

The actress, who was nominated for an Academy Award for Wings of a Dove, has appeared in four of Burton's movies - including Big Fish and animation The Corpse Bride.

The couple are currently working on their fifth joint project, a musical adaptation of Sweeney Todd co-starring Johnny Depp.

Birth experience

Bonham Carter is the great-granddaughter of former prime minister Herbert Asquith.

She scored her first leading role at the age of 17 and shot to fame as a classic English rose in period films such as Howard's End and A Room With a View.

US film-maker Burton moved to the UK after the couple began dating in 2001.

They reportedly live in separate, but adjacent, houses linked by a corridor.

After the birth of their first child, Bonham-Carter said: "It's like an explosion of heart, love, everything - and it's extraordinary.

"It's changed everything. Everybody told me it would, and, of course, I didn't really listen, and there's no real way of describing it."

Burton, who was in the delivery room, recalled: "It was like my own private Alien movie.

"I'll tell you, it was the weirdest thing I've ever seen. It was amazing."