Police investigating the disappearance of Madeleine McCann are probing 18 house break-ins in Portugal by a lone intruder suspected of a string of sexual assaults.
Detectives with the Metropolitan Police hope to carry out investigations in Portugal within a week after a public appeal in March drew more than 500 responses from the public.
They were following 12 potential leads but that number has grown to 18.
The break-ins all occurred in the Algarve in the months and years before McCann vanished from a villa in the resort of Praia da Luz in 2007.
In half the reported incidents between 2004 and 2006, children were abused, including a 10-year-old who was assaulted in the same resort from which McCann disappeared while her parents dined with friends.
All but one of the fresh leads were reported to Portuguese police at the time they happened, among them a so-called "near miss" .
Det Ch Insp Andy Redwood, the senior investigating officer said: "I'm encouraged by the new information that has come to light as a direct result of the appeal in March.
"There has been a huge public desire to assist us with our investigation."
Dep Asst Comm Martin Hewitt said: "I am cautiously optimistic that in the not-too-distant future we are going to start to see activity."
Earlier descriptions of the intruder described him as emitting an unpleasant smell and speaking English badly. One victim said he was wearing a burgundy coloured long-sleeved top, while another said it had a white circle on it.