THE detective leading the review into the disappearance of Madeleine McCann has spoken of now having the "best opportunity" of finally solving the mystery of what happened to her.
Detective Chief Inspector Andy Redwood said his inquiry had access to all the available evidence in one place for the first time.
It will be five years ago next week since the three-year-old went missing from her family's holiday flat in Praia da Luz in the Algarve, as her parents Kate and Gerry dined with friends nearby.
There have been hundreds of possible sightings of her all over the world, but so far they have come to nothing.
Mr Redwood told the BBC's Panorama programme, being shown tonight, that his team of 28 detectives and seven civilian support staff were handling a large number of reports and documents from both Portuguese and British police along with private detectives.
He said: "The systems and processes that we are bringing will give us the best opportunity to find those investigative opportunities that we can then present to our colleagues in Portugal.
"Our initial estimates in terms of the amount of material we are facing is that it will be somewhere in the region of 40,000 pieces of information."
Asked if Madeleine's disappearance on 3 May, 2007 could be solved simply by reappraising documentary evidence, he said: "Anything is possible, and clearly, within that material, the answer could lie."
The Met detective is the senior investigator in the inquiry, which was established last May after prime minister David Cameron responded to a plea from Madeleine's parents to hold a UK police review.
To date the review has cost taxpayers £2 million while officers have made two trips to Spain and visited Portugal four times, most recently last week.
"We are drawing together information from three separate sources," said Redwood.
"The legal enforcement bodies within Portugal, the UK enforcement agencies of which the police are the main part, and also and unusually the private investigation world which as we know is an element that was used by Mr and Mrs McCann in the search for their daughter."