Portuguese authorities have searched wells as part of their investigation into the disappearance of Madeleine McCann, according to reports.

The Mirror reported that police and divers in the Algarve region examined three disused wells in Vila do Bispo for eight hours on Thursday.

The area is around 10 miles from the Praia da Luz resort, where Madeleine disappeared on May 3, 2007.

Multiple investigators were at the scene with specialist diving equipment to examine the wells, with the largest thought to be more than 13 metres deep.

According to the paper, Madeleine’s parents Kate and Gerry McCann have not been told on what grounds authorities searched the wells.

It was also reported the search sites are near a beach where suspect Christian Brueckner’s camper van was photographed in 2007.

The investigation into Madeleine’s disappearance was renewed in June after German authorities announced they were investigating Brueckner, a convicted German child sex offender.

Brueckner is known to have lived on the Algarve coast and his Portuguese mobile phone received a half-hour phone call in Praia da Luz around an hour before Madeleine went missing 13 years ago.

He is in jail in Germany for drug dealing, and is appealing against a conviction for the 2005 rape of a 72-year-old woman, also at Praia da Luz.

He has not yet spoken to investigators, who say they are convinced that he has committed other sex attacks.

Thursday’s searches come after Kate and Gerry McCann denied receiving a letter from German investigators stating “there is evidence or proof” Madeleine is dead.

The pair posted a statement on the Find Madeleine website last month to deny the reported claims, saying that the news caused “unnecessary anxiety to friends and family and once again disrupted our lives”.

The couple also said that they do not have a family spokesman, and are not actively paying any lawyers to represent them.

German prosecutor Hans Christian Wolters, who is leading the investigation into the main suspect in Madeleine’s disappearance, told the PA news agency that a letter had been written to the couple, but would not reveal what it said.

Mr Wolters said prosecutors have “concrete evidence”, but not “forensic evidence” that Madeleine was killed by the suspect and may “know more” than Scotland Yard, who are still treating the case as a missing person investigation.

The Metropolitan Police maintain their active investigation into Madeleine’s disappearance, Operation Grange, is a missing person inquiry as there is no “definitive evidence whether Madeleine is alive or dead”.

In the days after the renewed appeal, Scotland Yard said they received hundreds of tips to their Operation Grange team.