Portuguese detectives have described the information and map as "vague" but are nevertheless following up on the lead.
Police officers visited the village of Arao, which is 15km from Praia da Luz, on Wednesday evening and spent time investigating the fields and land in the area.
The letter to the newspaper about Madeleine McCann gives details of a dirt track north of Odiaxere in the Algarve, and says the body of the little girl is buried "north of the road under branches and rocks, around six to seven metres off the road," it is reported.
Near a cross and two question marks on the map, the writer of the letter has indicated the place where Madeleine can be found.
Police in the Netherlands are studying similarities between the new letter and one received by De Telegraaf, which gave the whereabouts of Belgian step-sisters Stacey Lemmens, seven, and Nathalie Mahy, 10 who were murdered in June 2006.
Madeleine McCann’s parents, Kate and Gerry McCann, have travelled across Europe in an attempt to find their daughter, and the news about her disappearance and the campaign to find the little girls has been very well publicised in the media.
