Madeleine McCann could have been abducted by a sex beast wearing a surgical mask.
Police found that a man carried out up to 28 attacks within 40 miles of the Portuguese apartment in Praia Da Luz, from where Madeleine disappeared on May 3, 2007.
It has crept into properties rented by families and many victims were British.
In one case, a seven-year-old girl from the United Kingdom woke up and found him lying next to her in bed wearing a medical mask.
A chilling reconstruction in the final episode of the eight-part documentary of Netflix, The Disappearance Of Madeleine McCann.
Investigators Anthony Summers and Robbyn Swan, who wrote a book on the case, said the masked intruder was one of 12 suspects that the police are probing.
Anthony said, "From what the girls told their parents later, the man had entered the room wearing a kind of medical mask. It had a strange smell."
Robbyn said that the resort company that ran the Ocean Club resort where the McCanns were staying had refused to comment on whether or not they knew about these sexual assaults.
He said the Foreign and Commonwealth Office declined to comment on why the British tourists had not been warned.
Of the McCann case, Robbyn rhetorically asked documentary producers: "Would they have left their children alone if they had known that he was a sexual predator?"
Other suspects include a man standing in a mother's living room with her three-year-old daughter.
As he ran towards him, he fled.
* The Disappearance Of Madeleine McCann is streamed on Netflix now