16 years after Madeleine McCann went missing, police prepare to search a dam near where she disappeared.

Content warning: This story mentions sexual assault and may be distressing to some readers.

Sixteen years after Madeleine McCann disappeared, police are preparing to search a dam in the first formal development in the case in Portugal in several years.

The three-year-old was on holiday with her family in Portugal's Algarve when she went missing in May 2007. 

A fire brigade spokesperson said police were preparing to start searches on Tuesday at a dam in the southern region of Algarve, about 50km inland from the beach resort where Madeleine was last seen. 

Police erected two tents beside the dam on Monday, Reuters TV footage showed.

The search is expected to take two days, according to Portuguese media SIC Notícias.

A source familiar with the investigation told Reuters the operation in Silves municipality was being carried out at the request of German authorities, who last year formally identified German man Christian Brueckner as an official suspect in the disappearance of Madeleine. 

German officials had no immediate comment.

Madeleine McCann police to begin new search of reservoir in Portugal, 16 years after she went missing https://t.co/19k8DQRPE9

— BBC Breaking News (@BBCBreaking) May 22, 2023

Portugal's investigative Judicial Police in charge of the operation declined to comment.

A separate source familiar with the investigation was not optimistic about the chances of a breakthrough in the long-running case, saying, "It will come to nothing."

Brueckner, a convicted child abuser and drug dealer, is behind bars in Germany for raping a 72-year-old woman in the same area of the Algarve from where Madeleine went missing.

German police said in June 2020 that Madeleine was assumed dead and that Brueckner was likely responsible. Brueckner has denied any involvement and has not been charged with any crime related to the case.

A German court last month threw out additional charges against him related to other Portuguese child rape and sexual assault cases, which meant the German prosecutors investigating the disappearance of  Madeleine no longer had jurisdiction to investigate it.

Maddie's parents, Kate and Gerry McCann, were questioned by Portuguese police as formal suspects in 2007, but police dropped their investigation the following year, citing a lack of evidence, and cleared them of any involvement.

The parents have since campaigned to draw attention to their daughter's disappearance, and British public figures from business tycoons to authors and soccer stars have made appeals for information.

Read more:

Two-year-old Julia Wendell is not Madeleine McCann. But it's more 'complicated' than a desire for attention.

If this has raised any issues for you, or if you just feel like you need to speak to someone, please call 1800 RESPECT (1800 737 732) – the national sexual assault, domestic and family violence counselling service. 

- With AAP.

Feature Image: Getty.