Madeleine McCann police hunt sex predator

Madeleine McCann went missing aged three in 2007. Picture: PA

The tanned, dark-haired man is suspected of breaking into 12 properties where British families were staying in the Algarve between 2004 and 2010.

Five girls aged between seven and ten were sexually assaulted in four incidents between 2004 and 2006, before Madeleine, aged three, vanished in 2007.

Detective Chief Inspector Andy Redwood said tracing the man was “a primary concern”.

DCI Redwood said: “The significant features of this offending – a man with a vile interest in young, white, female children, who he is attacking in their beds while they are on holiday with their families – have got a very close resonance to some of the features of Madeleine’s disappearance.

“We really need to identify the offender, to bring to a close the trauma and the tragedy that these families have suffered, and then seek to establish whether this is connected to Madeleine’s disappearance.”

The potentially linked break-ins had previously been discounted by Portuguese investigators because they were spread over a wide geographical area and there were no apparent attempts at abduction.

Four of the incidents were in Carvoeiro, six in the Vale da Parra, in the Praia da Gale district, and two in Praia da Luz, the area where Madeleine went missing.

Nine of the 12 incidents were reported to Portuguese police at the time, but British investigators only became aware of three of those when the victims came forward in response to televised appeals last autumn.

In six of the offences, the man sat on or got into bed with young girls. Even when he was disturbed, witnesses said he remained calm. He spoke English slowly, with a foreign accent and possibly slurred speech, had unkempt hair, was unshaven, and smelled strange. Some witnesses said he had a pot belly.

In two of the break-ins, he was wearing a distinctive burgundy long-sleeved top, which some witnesses said had a white circle on the back.

DCI Redwood said that, if names were put forward for the most serious assault, his team would be able to eliminate suspects from their inquiry. This suggests that police have DNA on file.

The investigators have 38 people classed as “persons of interest” in the investigation and are 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.

Last autumn, the Scotland Yard team appealed for help in identifying a man seen carrying a child towards the sea on the night that Madeleine vanished, and a group of men seen loitering near the holiday apartment where her family was staying.

So far, they have not been able to eliminate any of the men from their inquiry.

British investigators have sent three international letters of request to Portuguese authorities for help with their inquiry, involving 287 separate requests.

Metropolitan Police deputy assistant commissioner Martin Hewitt said he was frustrated at how slow the legal process was working. “We know what we want to do and we are ready to go with that. But the process is the process.”

Another 30 letters have been written to other European countries, but the force would not reveal where.