Madeleine McCann's abductor may have been caught on camera by a spy plane on a training exercise for Nato, it was claimed today.
Military expert Philip Burden said highly-detailed aerial pictures were taken of the Portuguese coastline on the day the child went missing six-and-a-half years ago.
Mr Burden, a former Ministry of Defence employee, claimed the Portuguese Air Force then passed on the film to Portuguese police investigating Madeleine's disappearance.
It is believed the spy cameras used are so detailed they can pick out the registration number on a car if a good image is taken.
If high quality images are available, detectives could use them to piece together what happened on the day Madeleine disappeared, he said.
Mr Burden told The Sunday Express: 'The aircraft may provide a new lead in the hunt for Madeleine.
'During the early and late evening of May 3, 2007, the day Madeleine disappeared from the holiday resort of Praia da Luz, the plane took aerial photos of that stretch of the Algarve.'
Mr Burden added: 'I'm told there were a number of low-level passes over the resort as part of a lengthy photo reconnaissance training mission. Although the light was fading, people and buildings could be clearly seen.'
The Portuguese shelved their inquiry into her disappearance in 2008, but in October said that a review had uncovered enough new information to justify reopening the case.
British police received hundreds of calls and emails after renewed television appeals for information in the UK, Holland and Germany.
They appealed for help trying to trace a man who was seen carrying a child towards the sea, and a number of fair- haired men who were lurking around the holiday apartments where Madeleine was staying.
Last month, it emerged police were planning to reinterview several employees at the Ocean Club, the hotel where the McCann family were staying.
More than 130 workers were questioned during the initial inquiry, including two men who fixed a blind in the McCanns' apartment two days before Madeleine disappeared.
Nato were not available for comment.
- Daily Mail