A Scotland Yard team has travelled to the Algarve after a letter was sent to Portuguese police asking for help to trace three suspected burglars spotted in the area where Madeleine vanished nearly seven years ago.
The team, headed by Detective Chief Inspector Andy Redwood, who is leading the Metropolitan Police investigation, are said to have met members of Portugal's Policia Judiciaria (PJ) and prosecutors.
The PJ confirmed a meeting between "English and Portuguese authorities" had taken place in Faro but said it could not give details. The meeting followed an international letter of request.
A source was reported to have said that Madeleine's parents Kate and Gerry, who is from Glasgow, would be on "tenterhooks" as they waited for developments.
Madeleine, who was then nearly four, disappeared from the holiday apartment on May 3 2007 as her parents dined at a nearby restaurant with friends.
British detectives launched a fresh investigation into the youngster's disappearance last July.