Madeleine McCann. | Ultima Hora

Portuguese Judicial Police have reportedly been searching several wells in the Algarve looking for the remains of Madeleine McCann, who disappeared 13 years ago, but didn't find anything.

The search was concentrated in the Municipality of Vila do Bispo about 15 kilometres from the Praia da Luz apartment where Madeleine, her parents and siblings, Amelie and Sean were staying on holiday.

After more than a decade of searching, British, Portuguese and German authorities announced last month that they had a new suspect.

He is a 43-year-old German known as Christian B. who was living in the Algarve between 1995 and 2007 and is currently serving a prison sentence in Germany for another crime.

Police say he has a long history of crime, including drug trafficking, theft, sexual assault on minors, rape and child pornography.

The German Prosecutor's Office named him as their main suspect in the alleged kidnapping and murder of Maddie and several witnesses have emerged in Germany, Britain and Portugal who appear to reinforce suspicions that he was involved her disappearance.

He is also being investigated in relation to other missing minors in Germany and the Netherlands.