LONDON (AP) — The disappearance of 3-year-old Madeleine McCann in 2007 while her British family was on vacation in the Algarve resort region of Portugal has been a mystery for 16 years.

Investigators renewed their search for her Tuesday at a reservoir not far from where she went missing. Divers searched the waters as police dug and scraped up earth next to a dam.

The case has received attention around the world with each development, including a papal visit, numerous suspects being named and erroneous reports of sightings.

Here’s a timeline of events in the disappearance:

May 3, 2007: Madeleine is reported missing from a vacation apartment in the town of Praia da Luz in the Algarve resort region. Her parents, Kate and Gerry McCann, left her asleep with two smaller siblings while they had dinner at a nearby restaurant, and said they checked frequently on the children. They say Madeleine was kidnapped.

May 6, 2007: Police say there is evidence the girl was abducted, and appeal for her return.

May 11, 2007: David Beckham and other soccer stars appeal for Madeleine’s safe return. Police in Portugal scale down local searches, saying the case has become an international investigation.

May 12, 2007: Madeleine McCann's fourth birthday.

May 13, 2007: Harry Potter author J.K. Rowling pledges a contribution to a $3 million reward for the safe return of the child.

May 18, 2007: A website set up to help find Madeleine receives 65 million visitors in two days.

May 30, 2007: The McCanns meet with Pope Benedict XVI at the Vatican to discuss their ordeal. The pontiff pledges to pray for her safe return.

Aug. 3, 2007: Authorities in Belgium investigate a reported sighting of the child in the town of Tongeren. Police issue a drawing of a Dutch-speaking man reportedly seen with the girl and an English-speaking woman at a table outside a pub. Authorities eventually carry out DNA tests on a milkshake bottle from the pub, but the girl's DNA isn't found.

Aug. 7, 2007: Portuguese media report that search dogs found traces of blood in the hotel room where Madeleine went missing. The forensic evidence is sent to Britain for testing.

Aug. 11, 2007: Police say new evidence prompts them to consider the possibility the girl is dead 100 days after her disappearance.

Sept. 7. 2007: Gerry and Kate McCann are called in for questioning by police and named as suspects. They aren't charged and are allowed to leave the country.

March 19, 2008: British tabloids the Daily Express and the Daily Star print front page apologies to the McCann's as part of a 1 million pound ($1.24 million) settlement in a libel case. They acknowledged there was no evidence to support claims they caused their daughter’s death.

July 21, 2008: Portuguese authorities halt their investigation and say the McCanns are no longer suspects.

May 12, 2011: Kate McCann publishes a book about the disappearance on what would be her daughter's eighth birthday.

April 25, 2012: British police say they believe Madeleine could still be alive and release a picture of what she might look like as a 9-year-old.

July 4, 2013: British police say they have launched Operation Grange, after two years of reviewing the investigation. Police say they identified 38 people of interest, including 12 Britons.

Oct. 24, 2013: Portuguese police reopen case based on new evidence.

June 3, 2014: Search dogs and investigators search an area of scrubland near where Madeleine went missing.

April 28, 2015: A Portuguese judge awards the parents 500,000 euros ($539,000) in a libel action against the detective who published a book alleging they were involved in their daughter’s disappearance.

July 29, 2015: Australian authorities say DNA tests rule out Madeleine McCann in efforts to identify the decomposed remains of a young girl found in a suitcase dumped in bushes near Adelaide.

Sept. 16, 2015: The U.K. says its investigation into the disappearance has cost more than 10 million pounds ($12.4 million). A month later, police reduce the number of officers working on the case from 29 to four.

April 19, 2016: An appeals court in Portugal overturns the libel verdict against the former detective who alleged the parents were responsible for Madeleine’s disappearance.

April 30, 2017: In an interview before the 10-year anniversary since their daughter’s disappearance, the parents say they're still holding out hope she'll be found alive. Gerry McCann said it was “devastating” not to have found her, but added: “No parent is going to give up on their child, unless they know for certain their child is dead."

June 3, 2020: Police in Germany announce that Madeleine is presumed dead and a German man convicted of a rape committed in Portugal in 2005 is a suspect.

July 29, 2020: German police complete a search for Madeleine at a garden plot outside Hannover.

May 4, 2021: The McCanns post a statement on the Find Madeleine website saying they still cling to the hope of seeing their daughter again as they prepare to mark her 18th birthday.

April 21, 2022: Christian Brueckner, the German inmate, is named as a formal suspect by Portuguese authorities. He was in the area where Madeleine disappeared in 2007.

May 22, 2023: Search begins at Arade reservoir, about 30 miles (50 kilometers) from Praia da Luz.

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