The anguished parents of Madeleine McCann are facing a nerve wracking day as police investigate claims their daughter's body is lying hidden only a few miles from where she was abducted.
An anonymous letter which said the four-year-old's body was buried in scrubland was sent to Dutch newspaper De Telegraaf and passed on to the Portuguese Policia Judiciaria (PJ).
It was thought to pinpoint an area north of Odiaxere, nine miles north east of Praia da Luz from where the girl was snatched 42 days ago.
Police officers visited the village on Wednesday night, looking at fields and the surrounding area ahead of potential searches on Thursday.
It is understood that the PJ 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 15km 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 De Telegraaf, 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. It was only when it was translated from Dutch to English that they realised the significance of its contents.