A retired detective who has privately investigated the disappearance of Madeleine McCann believes her kidnappers are being protected.
Former Det Insp Dave Edgar handed his files over to the Met Police in 2011, when they took over the search and he believes the case can still be cracked.
He told The Mirror: “Someone knows, it must be on someone’s conscience.
“If anyone confided in you, now is the time to come forward.”
Madeleine was nearly four when she vanished in 2007 from her family’s holiday apartment in Praia da Luz as her parents dined with friends at a tapas bar nearby. The McCanns have spoken of their bitter regret about leaving her and two-year-old twins Sean and Amelie alone. The missing girl would now be a teenager and the family have never given up the search and remain hopeful she is alive.
Edgar also revealed he had probed her parents Kate and Gerry McCann, but found no shred of evidence they had anything to do with Madeleine’s vanishing.
He is certain the little girl was taken by a lone kidnapper or gang, that the motive was sexual and that it was a carefully planned abduction.
He also warned they could strike again: “It’s the type of crime they cannot help themselves, certainly if it was sexually motivated.”
He added: “There was a very narrow window of opportunity for them to get away with Madeleine. So it does point to it being planned and some level of surveillance, perhaps of the apartment.”
Edgar and his team also profiled a number of suspects named over the years, including late convicted paedophile Raymond Hewlett, who lived close to where Madeleine was taken from, and Euclides Monteiro, a former worker at the resort the McCanns’ stayed at, who died in a tractor accident in 2009.
There was no definitive evidence against either man, Edgar found.
As the 10th anniversary of Madeleine’s abduction approaches, Edgar is pushing for a Europe-wide appeal, believing whoever is responsible will have shared their secret.
He said: “They can’t keep it to themselves and research has shown they always confide in someone else.
“I think someone else apart from the perpetrator knows and that is one of the best hopes of getting to the truth, the someone comes forward and says what they know.”
Portuguese and British detectives are now united in probing fresh tips that Madeleine was spirited away by traffickers and the current investigation is reportedly on human traffickers who may have snatched her and sold her “to order.”
The Home Office has granted officers £85,000 to cover “operational costs” to continue the search.
Private investigators hired by the McCanns in 2007 reported the presence of men watching children at the beach with binoculars and taking pictures of them.
The McCanns believe images of their daughter may have been shared with traffickers who then selected her.
Officers are currently hunting a former Ocean Club worker who was at the resort when she vanished almost ten years ago.
While there is no suggestion the employee, who is said to be a Portuguese man who speaks some English, was involved directly in Madeleine’s disappearance, it is thought he may have information.
A British re-investigation into case was launched in 2011 after the initial one by the Portuguese authorities was deemed insufficient.