ABOVE: Portuguese police files on the Madeleine McCann case are made public

Files from the Portuguese police investigation into Madeleine McCann's disappearance have helped her parents to "draw strength" because of the lack of any evidence that their daughter is dead, the family spokesman said.

Gerry and Kate McCann's spokesman Clarence Mitchell said the newly-released files have revealed no evidence suggesting Madeleine had been killed or even harmed in the 15 months since she went missing on a family holiday in Portugal.

"The longer it goes on, they actually draw strength from that," he told the BBC. "They hope against hope she is being held somewhere."

Fresh revelations from the Portuguese police files are expected. Documents made public from the exhaustive inquiry have already revealed that detectives claimed the young girl's DNA had been found in her parents' hire car, despite a British scientist's warning days earlier that tests were inconclusive.

A family friend accused Portuguese officers of trying to extract a confession from Madeleine's father, Gerry McCann, by lying about the results of forensic analysis.

The Portuguese authorities released the police files on Monday after lifting the period of judicial secrecy in the case. Journalists were handed DVDs containing copies of thousands of pages of evidence from the case outside the court in the Algarve town of Portimao.

The dossier includes details of the lines of inquiry pursued by detectives, forensic reports, pictures of the bedroom where Madeleine was sleeping before she disappeared, witness statements and transcripts of interviews with Mr McCann and his wife Kate.

Lawyers for the McCanns, both 40, from Rothley, Leicestershire, were formally given access to the police files last week.

They are studying them for fresh leads that the couple's private detectives can follow up in their own search for their daughter.

The McCanns are keen not to give "a running commentary" on their legal team's trawl through the dossier, Mr Mitchell said. He said the priority was finding leads which could help to find Madeleine but told the BBC the team would be considering if there had been any "incompetency or anything worse" during the police investigation.