British detectives investigating the disappearance of Madeleine McCann are poised to stage operations on Portuguese soil.
Investigators from Scotland Yard are waiting for an official agreement later this week, and hope to begin "operational activity" linked to the case in the near future.
Deputy Assistant Commissioner Martin Hewitt said he hoped that Portuguese and British officers could act soon, although he would not reveal what the operations will involve.
He said: "I am cautiously optimistic that in the not-too-distant future we are going to start to see activity."
Police also revealed that they are looking at five more cases in which young British girls were sexually assaulted during holiday home break-ins by a lone intruder in the Algarve.
One of these was in 2005 on a 10-year-old girl in Praia da Luz, where Madeleine, then three, vanished two years later.