A DNA sample, said to be blood, was found on the window sill of the McCanns' apartment. There have also been reports of a second bloodstain on the floor.
But a small amount of Madeleine’'s blood in the apartment would not in itself be damning. Children frequently bleed from small cuts and abrasions and Madeleine would have been able to reach the sill.
is not known is how large a sample it
is. If blood was found over a large area
and later cleaned up, it could be seen
as evidence of an assault.
What did police find in the hire car?
Sources close to the investigation said on Monday that two samples found in the McCanns' Renault Scenic hire car had been found. One was in the cockpit and one in the boot, of which one was an exact match and another was a partial match.
Today police briefed the Portuguese media that "bodily fluids" - not blood - with an 88 per cent chance of being Madeleine's, were found in a space under the boot liner where the spare wheel is normally kept.
It was also claimed that large quantities of Madeleine's hair were in the car - so much, in fact, that it could only have come directly from her body, rather than being deposited by "secondary transfer" from her clothes or possessions.
The clear implication, if the reports are correct, is that Madeleine's body was transported in the car boot, in the wheel well.
The McCanns did not hire the car for 25 days after Madeleine disappeared, meaning they would have to have hidden the body for almost a month before disposing of it.
The couple have dismissed the suggestion as "ludicrous" and believe they are being framed.
have refused to give details about who
had hired the car between May 3, when
Madeleine vanished, and May 28, when the
McCanns started driving it. All other
drivers will have to be eliminated as
Ribeiro, the national head of the
Policia Judiciara, played down the
significance of the forensic evidence,
saying: "It is not true that a total
coincidence respecting the little girl's
DNA has been found. These results have
to be analysed rigorously and with
Could DNA evidence in the car show whether Madeleine was alive or dead?
Bodily fluids from a corpse will show signs of decomposition when analysed. This may explain why Portuguese police appear so confident that Madeleine is dead.
Similarly, blood begins to congeal after death and so blood samples can provide strong indications as to whether a person was alive or dead at the time they were deposited.
Another crucial factor is the quantity of blood or bodily fluids - a tiny speck of blood or a fleck of dried blood could have been transferred via Madeleine's possessions; a pool of blood could not.
Could DNA evidence tell police how Madeleine died?
If reports of Madeleine's hair being found in the car are correct, such a discovery could prove vital to determining whether Madeleine was, as some reports in Portugal have suggested, given an overdose of a sedative.
Traces of drugs in a person's blood are very quickly deposited in the roots of their hair, even if the drugs immediately cause death.
Such evidence was crucial in proving the guilt of Dr Harold Shipman, who murdered his patients with lethal doses of morphine. The drug was found in hair samples taken from his victims after they were exhumed, proving conclusively how they died.
If such analysis had been carried out on any hair samples found in the McCann case, it could explain why police have repeatedly asked the couple if they gave Madeleine sedatives.