There is mounting speculation about the contents - and strength - of the police dossier against Kate and Gerry McCann.

A Portuguese judge has started to examine the files into the disappearance of their four-year-old daughter Madeleine.

He has ten days to read the 4,000-page dossier and review the evidence complied by the Policia Judiciaria - Portugal's CID.

Legal experts said the judge has the power to order the couple back to Portugal and place them under house arrest.

Intense attention has focused on what exactly police found in the hire car rented by Madeleine's parents 25 days after she went missing.

Detectives denied reports that forensic tests on a sample taken from the vehicle, a silver Renault Scenic, had revealed a "100% match" with the missing girl's DNA.

Police spokesman Chief Inspector Olegario Sousa said: "That's not true. Even specialists have said there is no 100% in anything."

But senior sources linked to the investigation told Portuguese journalists they discovered "bodily fluids" - not blood - with an 88% match to Madeleine's genetic profile in the car's boot.

Police also found so much of the girl's hair in the car that it could not have been transferred from a blanket or clothes, and must have come directly from her body, one of the sources said.

Portuguese newspaper reports described the amount found as "clumps" of hair.

Other reports say the hire car - which is thought to have cost the McCanns a total of 8,000 euros to rent during their stay in Portugal - has now been seized by police.

Mr and Mrs McCann were declared "arguidos", or formal suspects, in the case during police questioning in Portimao last Friday.

At present they are only subject to the minimum TIR - "term of identity and residence" - restrictions.

These are automatically applied to an arguido under Portuguese law, and require them to give police their address and notify officers if they are away from home for more than five days.

This is why the McCanns were able to return to Rothley, Leicestershire, with their two-year-old twins, Sean and Amelie, on Sunday.