Madeleine McCann as she may look now

KATE and Gerry McCann have enrolled Oprah Winfrey in the search for their missing daughter, Madeleine.

The couple will use a high-profile interview with the American chat show host, which will be broadcast in 144 countries, to release new images of the child as she may look two years after vanishing.

The McCanns, who arrived in the United States yesterday, will visit the National Centre for Missing and Exploited Children in Alexandria, Virginia, where experts have created computer-aged pictures of Madeleine.

The couple, accompanied by spokesman Clarence Mitchell, and Emma Loach, director of a Channel 4 documentary to be shown after the 3 May anniversary of Madeleine's disappearance, will then fly to Chicago, where they will record the interview with Oprah, before returning to the UK early on Sunday.

Madeleine was nearly four when she went missing from her family's holiday flat in Praia da Luz, Portugal, on 3 May, 2007, while her parents dined with friends nearby. Despite a massive police investigation and huge publicity worldwide, she has not been found.

Yesterday, Mr Mitchell said the couple had agreed to appear on the US talk show because of its massive global reach. 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."

The couple now believe the Oprah interview will help in the search for their daughter.

Mr Mitchell said: "With the sheer scope of the (Oprah] programme – to be able to get the age-progression picture around the world – combined with the more in-depth Channel 4 documentary, they just felt that now was the right time."

The Oprah Winfrey Show interview is due to be broadcast in the US on 4 May, but it is not certain when it will be shown in the UK.

There has been a flurry of activity from the McCanns in recent weeks as they seek to capitalise on the heightened interest in the case around the anniversary.

In a message on the official Find Madeleine website, the couple wrote: "As the second anniversary of Madeleine's abduction approaches, there is much still to be done. We continue to remain focused on our aim – to find Madeleine and bring her back home safely.

"As Madeleine's parents, we cannot and will not ever stop doing all we can to find her."

Mr McCann, 40, also returned to Portugal over the weekend of 4-5 April to assist with the filming of a reconstruction of his daughter's disappearance.