Police in Portugal are preparing to scour wasteland after a tip-off that Madeleine McCann's body could be buried there.

An anonymous letter was sent with a map to a Dutch newspaper pointing to a site nine miles from Praia da Luz where the four-year-old was snatched.

Officers have not yet started a search because they are concerned the co-ordinates are not specific enough.

It is understood that the Portuguese Policia Judiciaria made a formal request to the GNR - a separate section of the police - to work together on the investigation.

Chief Inspector Olegario Sousa said the claims were being taken seriously and "everything necessary" was being done to validate the allegation.

"There have been exchanges between Dutch police and us," said Mr Sousa.

"The information indicated an area nine miles from the place of the disappearance of the little child.

"It is not far from Praia da Luz. We are checking the information like we check everything in this case for importance."

Asked if any search would involve digging, he said: "If the information gives us a precise location where we can look, we will do it."

According to reports, the letter said Madeleine was buried "north of the road under branches and rocks, around six to seven metres off the road" in a barren and deserted landscape.

A map from Dutch website routenet.nl came with the letter, with crosses marked on it.

The letter claimed her body could be found up a dirt track north of Odiaxere.

A source close to the family said they were with Portuguese police when news of the letter came through.

from : ITV Network Limited