(CNN) -- A team of 30 searchers will soon begin digging in an area in Portugal near where Madeleine McCann went missing in 2007, a source close to the investigation told CNN on Tuesday.
British police are leading the hunt for Madeleine, who was a few weeks shy of her fourth birthday when she disappeared from her family's holiday apartment in the country.
On Monday, media gathered outside a cordoned-off section of the beach resort town of Praia da Luz, in Portugal's Algarve region. A blue tent will cover the search area, and dogs will aid the search, the source told CNN. The land is extremely dry and covered in stones.
Madeleine's parents, Kate and Gerry McCann, left the girl and her younger twin siblings asleep in the apartment on May 3, 2007, while they went for dinner with friends at a tapas restaurant nearby. Her mother checked on the children about 10 p.m. and discovered her daughter missing.
CNN understands that London's Metropolitan Police will be in charge of the new digging operation in abandoned terrain close to where Madeleine disappeared. A large investigation team is expected to also use radar in the search.
Portuguese police searched the area soon after Madeleine's disappearance, and it is understood they will intervene only if remains are found.
Sources told CNN that British police were working on the assumption that Madeleine was dead, while their Portuguese counterparts were working on the assumption that she was still alive and had been taken out of Portugal by a non-Portuguese national who had been in the country for a short time.
Scotland Yard -- as London's Metropolitan Police are known -- has not commented on the latest development, other than to confirm that British officers would be in Praia da Luz this week.
On May 22, its head of specialist crime and operations, Assistant Commissioner Mark Rowley, told media there would be "specific police activity" in Portugal in the coming weeks, relating to Madeleine's disappearance.
"It should not be assumed that this substantial upcoming phase of work in Portugal will immediately lead us to the answers that will explain what has happened," he warned. "What you will see is normal police activity you would expect in any such major investigation."
Rowley said the senior investigator in the case, Detective Chief Inspector Andy Redwood, and his team would be traveling to Portugal but would not be commenting on the investigation.
He reiterated that Portuguese police had advised Metropolitan Police that they did not brief media on current investigations.
"They clearly stated that if the MPS (Metropolitan Police Service) provide any briefings or information on the work they are undertaking on our behalf, or if reporters cause any disruption to their work in Portugal, activity will cease until that problem dissipates," Rowley said.
"We have made it clear to colleagues in Portugal that we will not be giving operational updates," he said. "If media interfere with police work, that work will stop."
In July 2013, Scotland Yard reopened its investigation into Madeleine's disappearance after a two-year review of the original probe. Portuguese police reopened their investigation last October.
Madeleine's parents launched a massive publicity campaign to find their daughter after she went missing and say they continue to believe she is still alive.