Detectives investigating the disappearance of Madeleine McCann were today due to begin questioning 11 people.
British police working on the hunt for the missing girl are thought to have arrived in the Algarve to take part in interviews with individuals who it is thought may have information relating to the case.
They will spend three days working on the case alongside their Portuguese counterparts.
Scotland Yard has declined to comment.
The delegation in Portugal is believed to include the incoming head of the British side of the investigation after it emerged last week that the officer who has led Operation Grange since it was launched in 2011 is to step down.
Detective Chief Inspector Nicola Wall will officially replace retiring Detective Chief Inspector Andy Redwood on December 22.
Scotland Yard said a handover was currently taking place and Kate and Gerry McCann had been informed.
British officers spent eight days searching three areas of land in the Algarve resort of Praia da Luz in June, close to where Madeleine disappeared more than seven years ago, but found no new evidence.
Madeleine, then aged three, disappeared from her holiday apartment on May 3, 2007 as her parents dined at a nearby tapas restaurant with friends.
Portuguese police closed down their probe in 2008.