Portuguese police say they have found firm DNA evidence that the body of Madeleine McCann was in the family's hire car five weeks after she went missing, sources have told Sky News.
Sky crime correspondent Martin Brunt, speaking from Portimao, said police felt the find was "damning" evidence yet.
He said the sample of blood sent to the Forensic Science Service in Birmingham carried three matches of Madeleine's DNA.
"The samples that came back last week produced three matches to Madeleine's DNA," Brunt said.
"In the apartment police found one full match on a windowsill. That perhaps is not so important as Madeleine had been staying in the apartment for two weeks.
"In the hire car, five weeks after Madeleine's disappearance, police found a partial match.
"That might be explained by transfer onto clothes.
"But the crucial thing is that police have also found a second full match.
"Police say that is the most damning evidence that has been returned by the tests.
"It shows, as far as they are concerned, the presence of Madeleine's body in the car five weeks after she disappeared."
Brunt said the DNA was found in the boot of the hire car.
A partial match of DNA could be explained by particles of hair or skin from Madeleine's toys being put in the car, Brunt said.
But he said the full DNA match that had been found was more difficult for the McCanns to explain.
"According to police, the sample could not have come from a transfer. Blood on a body that was five weeks old would not have produced such a confident and full match," he said.
Meanwhile, papers outlining any evidence against Gerry and Kate McCann will be passed to the Public Prosecutor in Portugal, probably on Tuesday.
With the couple back in their home in Rothley, Leicestershire, the prosecutor will consider whether to lay any charges.
He will be considering the circumstances surrounding Madeleine's disappearance on May 3, Portuguese police spokesman Olegario Sousa added.
Brunt said the prosecutor had a number of options and may call for more evidence or advise on the investigation.
Family spokesman Brian Kennedy, who is Madeleine's great uncle, said of the family: "They are holding up extremely well."
The Portimao-based prosecutor, Jose Cunha de Magalhaes e Meneses, will look at the DNA evidence as well as the statements given by the McCanns to see if there is a case against the couple.
Chief Inspector Sousa said Portuguese police decided to pass the file on to the prosecutor despite not having all the results from forensic tests being carried out in Birmingham.
The samples were taken from the McCanns' holiday apartment and hire car.
The McCanns have been told they could be called back to Portugal "at any time".
Under Portuguese law the couple could keep their arguido - suspect - status for up to eight months, although the prosecutor could decide to extend that to a year.
Portuguese detectives appear to be working on the theory that Mrs McCann killed her daughter by accident and covered up the death by claiming she was abducted.
According to reports in Portugal, police are to make new searches as part of the investigation.
