Enlarge By Marco de Swart, Reuters A man reads a copy of the Dutch newspaper De Telegraaf in Amsterdam Friday. The paper reported that it received an anonymous letter describing a possible location where the "body" of the missing British girl Madeleine McCann could be found in Portugal. The headline reads "body of Madeleine near apartment."

Police investigating Madeleine's disappearance from a Portugese hotel more than a month ago said they were checking the tip which appeared in a Dutch newspaper Wednesday and was widely reported.

The paper said it had given police an anonymous letter it received with a map showing a remote location in southern Portugal where Madeleine might be buried.

The girl's father, Gerry McCann, said in a blog on his website that the family were "extremely disappointed" by the revelation.

"Although all information will be taken seriously, we were very upset that the credibility of this letter had not been examined and, more importantly, published before the Portuguese police had an opportunity to investigate the claim, and search the area if appropriate without massive media attention," he wrote.

"We feel strongly that this was an irresponsible piece of journalism and even if it were true is insensitive and cruel. One can imagine how upsetting it is for Kate and I to hear of such claims through the media and if every piece of information was published like this there would be nothing else in the newspapers."

Police had said they may use sniffer dogs to search the area marked on the map, but no police could be seen in the general area, local media reported.

The location marked on the map is remote scrubland about nine miles from where the girl vanished while on vacation with her family.

Police say they have followed up dozens of leads, included reports of sightings of Madeleine by the public, but none has yielded results.

Madeleine disappeared on May 3 from a hotel in Praia da Luz, a resort town in Portugal's Algarve region. Her parents left her and her 2-year-old twin siblings alone in their hotel room while they dined at a nearby restaurant.

Since then, the couple has launched an international campaign to find the girl, enlisting the aid of celebrities including soccer star David Beckham and J.K. Rowling, author of the Harry Potter series.

Kate and Gerry McCann have also traveled to Spain, Germany, the Netherlands and Morocco to plead for help in finding their daughter. They fear Madeleine may have been taken out of Portugal but say they have no plans to return to Britain without her.

They also visited the Vatican, where Pope Benedict XVI blessed them and a photograph of Madeleine.