Exclusive: Key forensic tests back police suspicions that Kate McCann accidentally killed her daughter Madeleine. 

Madeleine McCann (PA)

Key forensic tests back police suspicions that Kate McCann accidentally killed her daughter Madeleine and the body was then moved by car, it was claimed yesterday.

Experts found differences in Madeleine's blood traces taken from the family apartment in Praia da Luz and the Renault Scenic Kate and husband Gerry rented 25 days after the four-year-old vanished on May 3.

They say specks found on the floor and window sill of the apartment were fresh before they dried.

But blood and other bodily fluids found in the boot lining and interior of the Renault congealed differently, indicating they came from Madeleine's body at a later time.

The samples reportedly had a "full match" with Madeleine's DNA.

Police have since commissioned further tests and analysis of samples based on answers given by Kate and Gerry during interviews. They suspect Gerry helped cover up his daughter's death by disposing of her body then lying about events.

The results from Britain's Forensic Science Service emerged as detectives prepared to give prosecutors a dossier calling for Kate to be charged with "accidental homicide", the Portuguese equivalent of manslaughter in British law.

A source said: "The feeling is that the forensics support the theory that Madeleine died accidentally inside the apartment on the night she vanished, and she was then moved.

"These are sensitive tests but they have been carried out by some of the best scientists in the world. Detectives believe they fit into a wider pattern of evidence which points to the McCanns.

"There has been talk of 70 or 80 per cent matches. The FSS doesn't do that. It's either a match or it's not. It's either significant or it's not. In this case, it's significant."

Last night it was also believed phone taps may have been used. Unlike Britain, covert recordings are allowed as evidence in Portuguese courts.

Yesterday officers in Praia da Luz began a fresh search of the villa the McCanns rented after leaving their holiday apartment. They are looking for more traces of blood, fibres and other bodily fluids which may be linked to Madeleine.

Further searches at other nearby sites will be carried out. One place under scrutiny is in the nearby town of Lagos where officers will check drainage systems and construction sites.

Fishermen have reported being asked to search coves along the Algarve coast for bin liners.

The police dossier of evidence against the McCanns contains hundreds of pages of interview transcripts, witness statements, forensic reports and analysis by detectives.

It will be handed this morning to Jose Cunha de Magalhaes de Menezes who will decide if the couple, both 39, have a case to answer.

Mr de Menezes is expected to wait for a further update from British scientists before announcing if Kate and Gerry should face trial.

Police spokesman Chief Inspector Olegario Sousa said yesterday: "At the moment the inquiry is being prepared to be handed to the prosecutor. He will analyse it then make his decision."

Hunt leader Guilhermino Encarnacao added: "The theory of the death of Madeleine is progressively gaining more consistency. The investigation continues with all means."

A source close to the inquiry said all major results had been handed to British police and the Portuguese authorities. The insider added: "We have reached the tail end."

There were claims that the prosecutor would have charged the McCanns last week. But it is thought he was pressured into waiting by the Portuguese Attorney General.

Police believe the implications of a botched trial for relations between Portugal and the UK, and the effects on tourism, played a part.

The prosecutor now has three options - to bring charges, rule no action should be taken, or return the papers to police requesting more evidence. Under Portuguese law the McCanns have to be notified of any impending prosecution in writing.

It could mean months of waiting for the heartbroken couple who vehemently insist they had nothing to do with Madeleine's disappearance and believe their daughter was abducted.

Relatives say it is ludicrous to think Kate and Gerry could have hidden a body for 25 days then moved it while constantly in the public eye.

One witness believes she saw a mystery man carrying a child near the McCanns' apartment on the night Madeleine disappeared.

Furious relatives accuse the police of attempting to frame Kate and Gerry. Other supporters have even suggested crucial evidence has been planted to avoid accusations of a bungled inquiry.

Madeleine's aunt, Philomena, said: "All I can suggest is that the Portuguese police are clutching at straws to get this case cleared up.

"Kate and Gerry have been a thorn in their sides for a long time. What better than to cast them as villains ?" The McCanns were named as suspects last week after being questioned as witnesses.

Detectives told Kate during questioning that if she confessed to accidentally killing Madeleine she would get a reduced sentence of two years.

The couple were not set bail conditions and were allowed to return home to Rothley, Leics, with twins Sean and Amelie, two, on Sunday.

They insisted they were not running away and would continue to co-operate.

They have since hired top barrister Michael Caplan QC, an expert in extradition law who represented Chilean dictator General Pinochet in 1999.

He will be instructed by solicitor Angus McBride who defended actor Chris Langham, convicted of downloading child porn.

A family friend said the McCanns were being advised on "much more than just extradition" but would not give any further details.

Kate and Gerry now have the headache of meeting hefty legal bills to try to prove their innocence.

So far more than #1million of donated money has flowed into the fund set up to find Madeleine. But using fund money is not an option.

FORENSIC EVIDENCE

Analysed by Detective Chief Inspector Peter Kirkham, former Scotland Yard murder squad investigator

Clue: Blood on window sill of apartment at Ocean World resort which matches Madeleine's DNA profile

Dci Kirkham says: "She could have reached this herself which means it is not necessarily suspicious. She could have cut herself or bumped into it so it is of interest but not significant on its own."

Clue: Blood on floor of apartment at Ocean World resort which dried fresh and matched Madeleine's DNA profile

Dci Kirkham says: "Children can fall over and bump themselves and it's unlikely that they do themselves a lot of harm. The significance of this depends on how much and the spray or pattern it forms."

Clue: Police teams still searching for Madeleine in surrounding and wider area of Portugal

Dci Kirkham says: "To find a body in any murder is absolutely crucial even after several months. It moves an investigation forward a million miles with new leads. There are soil samples to examine, other forensic traces to detect and items to examine. Without a body, you are at step one, with a body you are at step nine."

Clue: Blood, hairs and other bodily fluids in interior and boot lining of Renault Scenic

Dci Kirkham says: "This is much harder to explain away innocently. If there is more than a few spots that suggests something sinister. If there is bodily fluid from a decomposing corpse it is almost impossible to come up with an innocent explanation."

Clue: Search of the nearby villa which Kate and Gerry McCann rented after they left Ocean World Resort

Dci Kirkham says: "If the police believe a corpse has been moved they will ask, 'Where was it wrapped?' If there are traces in the car there would have been traces on clothes. If there were traces on clothes they could have been transferred to the villa."

Clue: Cuddle Cat, which Kate says she left with Madeleine but she says was found on a shelf afterwards

Dci Kirkham says: "This was given as evidence that Madeleine did not wander off. But Portuguese police will not take it at face value now Kate is a suspect."

Jon.Clements@Mirror.Co.Uk