Detectives investigating the disappearance of Madeleine McCann are looking for a lone intruder who sexually abused five girls during break-ins at holiday homes
Detective Chief Inspector Andy Redwood said tracing the tanned, dark-haired man man, said to have "an unhealthy interest in young white female children", is one of his priority lines of inquiry.
The man is suspected of breaking in to 12 properties where British families were staying in the Algarve, Portugal between 2004 and 2010.
In the incidents girls aged between seven and 10 years of age were sexually assaulted.
These attacks happened between 2004 and 2006, before Madeleine vanished in 2007.
His team currently have 38 people classed as "persons of interest" to the inquiry, and are also sifting through details of 530 known sex offenders whose whereabouts they cannot account for.
Of those 59 are classed as high priority, and some of those are British.