THE ongoing review of the Madeleine McCann case offers the "best opportunity" to solve the mystery because it is the first time information from all sources has been pooled, a detective has claimed.

Det Chief Insp Andy Redwood, who is leading the UK police hunt for missing little girl, said his team was sifting through around 40,000 pieces of information with the sole aim of solving the case.

 Madeleine was nearly four when she went missing from her family's holiday flat in Praia da Luz in the Algarve almost five years ago, on May 3 2007, as her parents Kate and Gerry McCann dined with friends nearby.

 The official inquiry was formally shelved in July 2008 but Scotland Yard’s review of the case, called Operation Grange, was launched last year at the request of Theresa May, the Home Secretary, in response to a plea from the McCanns.

DCI Redwood said his team of 28 detectives and seven civilian staff was in the process of turning over “every single piece of paper” generated in the investigation and interpreting and analysing everything they contained.

He said: “Anything is possible, and clearly, within that material, the answer could lie."

The team is drawing together information from three separate sources: Portuguese legal enforcement bodies, British legal enforcement agencies, which include the police, and the private investigations commissioned by Madeleine’s parents.

 Asked why he believed the operation was unique, DCI Redwood told BBC Panorama: “Because at no time before have those three elements been drawn together in one place. And so what we’ve done over the past number of months is to bring to one place all those pieces of the jigsaw.”

He added: “I am satisfied that the systems and processes that we are bringing to this set of circumstances will give us the best opportunity to find those investigative opportunities that we can then present to our colleagues in Portugal.”

Operation Grange has so far cost the tax payer £2 million. Officers have made two trips to Spain and visited Portugal four times, most recently last week.

But while Portuguese police remain the lead agency on the case, DCI Redwood said his team in London aimed to solve the mystery.

“We are here in terms of seeking to bring closure to the case,” he said. “That would be the ultimate objective and is our ultimate objective. Closure means establishing what has happened to Madeleine McCann.”

Goncalo Amaral, the former detective who lead the original case before being removed after criticising British involvement, admitted making mistakes.

“It’s a fact that our investigation had its faults and lost a lot of time, lots of time,” he told the programme. “And a lot of things didn’t get followed up. And I’m just as much to blame for that as anyone else.”

Since leaving the police in 2008, Amaral has written a book and presented a DVD about Madeleine’s disappearance, in which he makes allegations against her parents, Mr and Mrs McCann, from Rothley, Leicestershire, who are now suing him for libel.

In March, a new team of detectives from Porto, northern Portugal, was brought in to re-examine the case, which the McCanns' Portuguese lawyer Rogerio Alves described as a "very positive sign".

The latest alleged sighting of Madeleine was made earlier this month in the Costa del Sol.  

BBC Panorama – Madeleine: The Last Hope? will be shown on Wednesday April 25 at 7.30pm on BBC One.  

- Victoria Ward