LONDON — British police investigating the disappearance of Madeleine McCann said Wednesday they are seeking an intruder who sexually assaulted five girls in the region of southern Portugal where the British toddler was last seen.

Police have linked 12 crimes between 2004 and 2010, in which a man entered holiday villas occupied by British families in Portugal’s Algarve region. In several of those cases, the man sexually assaulted young girls.

Detective Chief Inspector Andy Redwood acknowledged there were differences between the characteristics of the 12 incidents and the McCann case – such as time of day and the fact that there were no abductions – but stressed the need to identify the intruder.

“This is an offender who has got a very, very unhealthy interest in young, white, female children who he is attacking whilst they are on holiday in their beds,” Redwood said. “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.”

British police haven’t released a composite sketch of the suspect.