Detectives investigating the disappearance of British girl Madeleine McCann in Portugal said yesterday they were looking for a lone intruder who sexually abused five girls after breaking into holiday villas.
The tanned, dark-haired man is suspected of breaking into 12 properties where British families were staying in the Algarve between 2004 and 2010, the Metropolitan Police said.
In four of the incidents, girls aged between seven and 10 were sexually assaulted while they were in their beds. In one case, two girls were assaulted in the same villa. However, no children were abducted.
The attacks happened between 2004 and 2006, before Madeleine vanished from a holiday apartment in 2007, days before her fourth birthday.
Her parents were dining with friends at a restaurant at the time.
Police see striking similarities between the break-ins. In most cases, there were no signs of forced entry to the property and the intruder appeared between 2am and 5am. The man, who spoke English with an accent, remained calm even when disturbed.
On two occasions the noise of a refuse collection lorry could be heard nearby. And two of the break-ins were in the resort of Praia da Luz, where Madeleine disappeared.
Detective chief inspector Andy Redwood said tracing the man, who was said to have "an unhealthy interest in young white female children", was one of his priority lines of inquiry.
"These offences are very serious and no one has been charged in connection with them," Redwood said. "We also need to eliminate this man from our inquires and ascertain whether these offences are linked to Madeleine's disappearance."
Redwood said there were differences between the other cases and Madeleine's disappearance, and that there was a possibility Madeleine had not left her family's apartment alive when she disappeared in 2007.
His team, which is working with Portuguese authorities, has 38 people classed as "persons of interest" and is also sifting through details of 530 known sex offenders whose whereabouts cannot be accounted for. Of those, 59 are classed as high priority, and some are British.
Portuguese authorities closed their investigation into the case in 2008, but the Metropolitan Police opened their own probe in July last year.
The missing girl's parents, Gerry and Kate McCann, have never given up their campaign to find Madeleine.
Additional reporting by The Guardian