Home Secretary Theresa May has agreed to fund the operation after Portuguese police failed to make any progress.
Madeleine, from Leicestershire, was almost four when she went missing on holiday from her family’s apartment in the resort of Praia da Luz in 2007.
Scotland Yard said her parents, Kate and Gerry McCann, were being kept fully updated on the progress of its work.
In a statement the Home Office said it “remains committed to supporting the search” and has agreed “to provide the Metropolitan Police with the resources they need to investigate her disappearance”.
A review into the case by police in the UK discovered new potential leads but the police in Portugal have not reopened the case.
Yesterday Scotland Yard would not comment on the latest development but released a statement saying they are encouraged by the progress they are making.
It said: “We are reviewing a significant number of documents and continue to identify potential lines of inquiry.
“We are in regular contact with Kate and Gerry McCann and they are kept fully updated.
The Met has issued a computer-generated image of how Madeleine would look aged nine.