Police investigating the disappearance of Madeleine McCann have taken away a number of bags from a search site in southern Portugal.
Officers have been combing a reservoir and surrounding scrubland after receiving “certain tip-offs”.
Police divers entered the water at the Arade dam in Silves municipality on Tuesday.
But it is not known what was in the bags.
The site is about 31 miles from where the British girl went missing during a family holiday in Praia da Luz in the Algarve on 3 May 2007. Madeleine was just three years old at the time.
German prosecutor Christian Wolter said: “We are investigating in Portugal on the basis of certain tips [tip-offs].
“I can’t disclose the background at the moment, like why we are searching there and what we hope to find there. That shall remain our secret for the moment.”
A source familiar with the investigation told the Reuters news agency the operation was likely linked to photographs of the reservoir found at the hideout of Christian B.
He was named by German prosecutors last year as an official suspect in Madeleine’s disappearance.
A boat was also sent into the reservoir with two officers. About 20 to 30 officers could be seen in the area, a dozen of which had sniffer dogs.
Vehicles and officers were first seen at the site of the reservoir on Monday after reports of the new search emerged.
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Local police said they are co-ordinating searches in the Algarve at the request of German police and in the presence of British officers.
It comes after German police announced in June 2020 that they believed Madeleine was dead and that Christian B was likely responsible.
It is claimed the convicted child abuser and drug dealer used to visit the reservoir, allegedly referring to it as “his paradise”.
Christian B is currently in prison for raping a 72-year-old woman in the same area of the Algarve region from where Madeleine went missing, but he has not been charged with any crime related to the disappearance.
He has denied any involvement.
Jon Clarke, author of My Search for Madeleine, after he was the first journalist on the scene when Madeleine went missing in 2007, said that Mr Wolter received the tip-off from a “credible source” in April.
Speaking to Sky News, Mr Clarke said that police are “optimistic” that they might also find the bodies of three missing children who have never been found, including eight-year-old Joana Cipriano, who went missing in 2004, “very near” to Praia da Luz.
The waterway was previously searched in 2008 after Portuguese lawyer Marcos Aragao Correia paid for specialist divers to check the site.
He claimed to have been tipped off by criminal contacts that Madeleine’s body was in the reservoir, but nothing was found.
A search was also carried out in 2014 of scrubland near where she vanished, after British police were given permission to investigate by Portuguese authorities.
A German court last month threw out additional rape and sexual offence charges against Christian B that were not linked to Madeleine’s case.
He had been accused of three offences of aggravated rape and two offences of sexual abuse of children in Portugal between December 2000 and June 2017.
However, the court in Braunschweig ruled it had no jurisdiction in the case.
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Lawyer Friedrich Fulscher said the decision meant court authorities could not have jurisdiction over any potential case about Madeleine either. The court did not comment on his claim.
Last year, on the 15th anniversary of her disappearance, Madeleine’s parents said it was “essential” to learn the truth of what happened to their daughter.
Kate and Gerry McCann also marked Madeleine’s 20th birthday earlier this month with a vow that they would “never give up” the search for her.