Madeleine McCann's parents hire US private investigators

The team are said to be taking over primary responsibility for the investigating into Madeleine's disappearance, although the Spanish firm Metodo 3, which has until now spearheaded the search, will continue to follow up information from Spain and Portugal.

The news comes shortly after Portuguese police shelved the case and released a 30,000 page dossier detailing their investigation.

The dossier has revealed thousands of potential sightings of the three-year-old following her disappearance from the family's rented holiday apartment in Praia da Luz in the Algarve on May 3 last year.

The US firm, which has not been named, is said to have been offered a £500,000 six-month contract by the Find Madeleine Fund, which has received donations from several wealthy benefactors and wellwishers around the world.