ARADE DAM, Portugal (AP) — Portuguese police aided by German and British colleagues on Tuesday resumed their search for Madeleine McCann, the British child who disappeared in the country’s southern Algarve region 16 years ago.

Between 20 and 30 officers, some in uniform, could be seen in the area by the Arade dam, about 50 kilometers (30 miles) from Praia da Luz, where the 3-year-old was last seen alive in 2007.

Portuguese police had set up a blue base tent and cordoned off the area to the media and public. Eyewitnesses said police began searching shortly before 8 a.m. Tuesday in an area some kilometers (miles) away from the tent. More than a dozen cars and police vans could be seen arriving in the area.

On Monday, Portugal’s Judicial Police issued a statement saying the search was being resumed at the request of German authorities and with help from British officials.

German prosecutors in Braunschweig said in a written statement Tuesday that “criminal procedural measures are currently taking place in Portugal as part of the investigation into the Madeleine McCann case.”

They added that “the measures are being implemented by way of mutual legal assistance by the Portuguese prosecution authorities with the support of officers from the Federal Criminal Police Office.”

“More detailed information on the background is not being released at this time for investigative tactical reasons,” the statement said.

In mid-2020, German officials said a 45-year-old German citizen, identified by media as Christian Brueckner, who was in the Algarve in 2007, was a suspect in the case. Brueckner has denied any involvement.

Brueckner is currently serving a seven-year prison sentence in Germany for a rape he committed in Portugal in 2005.

He is under investigation on suspicion of murder in the McCann case but hasn’t been charged. He spent many years in Portugal, including in Praia da Luz, around the time of Madeleine’s disappearance.

The case stirred worldwide interest for several years, with reports of sightings of her stretching as far away as Australia, along with a slew of books and television documentaries about the case.

Rewards for finding Madeleine, who would now be 20, reached several million dollars.

British, Portuguese and German police are still piecing together what happened on the night when the toddler disappeared from her bed in the southern Portuguese resort on May 3, 2007. She was in the same room as her twin brother and sister, who were 2 at the time, while her parents had dinner with friends at a nearby restaurant.