SCOTLAND Yard detectives have flown to Spain as part of their review of the Madeleine McCann case.
Officers spent three days with Spanish colleagues in Barcelona last month discussing Madeleine McCann's disappearance across the border in Portugal.
The Metropolitan Police force has said there would be no limits in its re-examination of the search.
Madeleine was nearly four when she went missing from her family's holiday flat in Praia da Luz in the Algarve on May 3 2007 as her parents Kate and Gerry dined with friends nearby.
Police have also travelled to Portugal three times in connection with the fresh review, the force said.
There were unconfirmed reports of a little girl being smuggled over the border from Portugal to Spain.
However, last night detectives were unwilling to discuss what led officers to travel to Barcelona to meet Spanish police between November 23 and 25.
A Scotland Yard source said: "There has been very good co-operation with Portuguese authorities and liaison will continue."
Detective Chief Inspector Andy Redwood, the senior investigating officer, was understood to be among a team of detectives who went on the trips.
A total of 30 people are now working on the force's 'Operation Grange'.