New analysis by a former Madeleine McCann detective shows that the woman who claims to be the missing girl is not possible, he says.
Julia Wendell from Poland went viral on social media after creating an Instagram account named @iammadeleinemccan which gained over 1 million followers. McCann disappeared during a family holiday in Portugal in 2007.
Wendell claims to have a freckle on her leg as well as a mark in her eye in the same place as McCann, and claims their family approached her to take a DNA test.
McCann was born in May 2003, meaning she would now be 19. However, Wendell is currently 21 years old.
Francisco Marco, who led the initial hunt for Madeleine McCann after her disappearance, has come out with an analysis, highlighting the lack of resemblance between McCann and Wendell.
"I have done a biometric search and there is no resemblance to Madeleine's features," detective Marco told Spanish network RAC1.
He said it was strange that Wendell had taken to social media before reaching out to McCann's family.
"I can think it's a fraud, but I can't say without evidence," he told RAC1.
When answering questions her followers were asking on Instagram, Wendell said she does not remember being taken away and had no recollection of most details of her childhood.
"I don't remember being taken away. I mean, I don't remember almost my entire childhood," she said.
Meanwhile, German investigators believe McCann was killed by sex predator Christian Brueckner.
Bruckner has repeatedly denied having anything to do with the young girl's disappearance.
A source close to the McCann family told the Daily Star Sunday that they are "willing to look at all leads".
"The family are taking no chances, they are willing to look at all leads. It is important they look at all of the factors, the girl does look similar. There's no disputing that," they said.