A former detective in the disappearance case of Madeline McCann believes someone "close to the group" may be hiding information from police about the girl's whereabouts.

The infamous investigation, which began almost a decade ago when the then-toddler was abducted on 3 May 2007, has sparked many theories about what may have happened to her and numerous rumoured sightings all over the world.

However, Paulo Pereira Cristovão, who became head of Portugal's missing children agency in the same year Madeline went missing, believes someone is withholding information about her disappearance but could not say what the motive for doing it would be.

"Someone close to those people, or someone from the group, still has not said all that he or she knows about this.

"That's my feeling – and I know there are many who think just like me. I think not everybody in that group has told the truth to the police. Why? I don't know."

Cristovão claims he had attempted to visualise the path of McCann's abductors, and says he has an idea of where they might have taken her – or potentially dumped her body.

"I put myself in the role of someone who knew nothing about the streets or the region. Where would I put the body of a girl?

"I stood at the apartment door – to the right is the town of Portimao. There are lots of people there, lots of buildings.

"If I had kidnapped her that's not the way I'd want to go. I would want to go left, and find the first side road. I put my car on that road, and I went straight to Burgau. It's a nearby beach, with a lot of rocks with caves.

"It's a good place to put somebody. As far as I know the police never went there, because you would need divers."

Richard D Hall
Gerry and Kate McCann speak to the press the day after their daughter, Madeline, went missing at a holiday resort in Portgual. Melanie Maps/AFP

He dismissed "stupid" theories that have been mooted over the years, such as an alien abduction, stating that people "complicate" things when they lack understanding.

The ex-investigator, who initially criticised the McCanns for leaving Madeline and their two other children alone in the hotel room while they dined nearby, does not think the parents had anything to do with the abduction.

Kate and Gerry McCann were classified as "arguidos" by Portuguese police in the early stages of the investigation, but that tag has since been dropped. The status of an "arguido", or "formal suspect", is similar to a person being questioned under caution by police in the UK or after having Miranda rights read in the US.

UK police have invested around £11m ($14.1m) in the bid to find Madeline and her abductors.

Madeleine McCann
British police released an image in 2012 that imagined how Maddie might look as she grew up. Reuters