Kate and Gerry McCann have flown to the United States for an interview on the Oprah Winfrey Show to mark two years since their daughter Madeleine's disappearance.

The couple will use their high-profile appearance on the TV programme to release new images of how their missing girl may look now.

They will visit the National Centre for Missing and Exploited Children in Alexandria, Virginia, whose experts have created the computer-aged pictures of Madeleine.

The show will also go inside the couple's London home to spend a day with their four-year-old twins Sean and Amelie.

Madeleine's brother and sister are now older than she was when she disappeared.

The McCanns flew out of Heathrow Airport with their spokesman, Clarence Mitchell, and Emma Loach, director of a Channel 4 documentary to be shown after the May 3 anniversary.

They will record the interview with Winfrey in Chicago tomorrow before returning to the UK early on Sunday.

Mr Mitchell said the couple had agreed to appear on the famous U.S. talk show because of its massive global reach - it is broadcast in 144 countries around the world.

He said: 'Oprah had been pressing for an interview from very early on.

'Initially Kate and Gerry were focused entirely on the search for Madeleine on the ground.

'They were reluctant to do a programme perceived by some as celebrity-based - they certainly didn't feel they were celebrities and were loath to do anything that had that feel about it.'

It was then 'inappropriate' for the McCanns to speak out after Portuguese police made them 'arguidos', or formal suspects, in the case in September 2007, he said.

But their arguido status was lifted last July and the couple now believe that the Winfrey interview will help the ongoing search for their daughter.

Madeleine was nearly four when she went missing from her family's holiday flat in Praia da Luz, Portugal, on May 3 2007 while her parents dined with friends nearby.

Despite a massive police investigation and huge publicity worldwide, she has not been found.