Madeleine was just three years old when she went missing in May 2007 during a family holiday in Portugal.
According to The Sun, David Edgar, a retired private investigator who previously worked on the case, is convinced Maddie was snatched by a child sex gang and is still alive and most likely being held hostage under a different identity.
“She is most likely being held captive, possibly in an underground cellar or dungeon and could emerge at any time,” says Edgar.
His comments come after news the investigation has been reignited with new funding after support for the cause had wavered over the last few years.
Edgar, who was employed by Kate and Gerry McCann for three years as a private investigator, passed on all his findings on the case to police in 2011, and says there were leads he was unable to follow up due to restrictions that would not be faced by official authorities.
Edgar believes the police have had a recent tip-off relating to her kidnappers, providing them with a new line of investigation.
“She could literally be anywhere in the world but my hunch is that she is in Portugal. The chance that she may have been smuggled out of the country without being detected is highly unlikely.
“There is someone in Portugal with an open knowledge of where she is and what happened. Someone knows what happened and it’s time they came forward — maybe they already have.”
“Unless a body is found there is hope. Everyone hopes for a positive outcome and Kate and Gerry will never give up, even when the funding runs out. I hope they get an answer they’ve been waiting for so long.”
If she is still alive, Madeleine would be 15 today.