ohn O’Connor said the spiralling cost of the four-year investigation and the seeming lack of progress meant the Met must now ask itself whether resources should be focused elsewhere.
He added: “If there are no firm leads, and by that I mean no substantial operational things like active surveillance on suspects, then I’d have thought they should be considering winding it down now.”
His comments come as a Sun investigation today reveals the Met’s inquiry into Madeleine’s disappearance from the Portuguese resort of Praia da Luz in May 2007 has cost taxpayers almost £11million.
At the current rate it will top £12million by April — more than double the £5million promised by David Cameron when Operation Grange was launched in May 2011.
The task force, which at its height was 37 strong, has yet to make a single arrest.
Tens of thousands of pounds have been spent on flights to Portugal and to investigate other sightings around the globe.
Mr O’Connor added: “You can’t keep chasing shadows. Chasing sightings all over the world. It depends on whether the detectives are making any real progress. For me it needs to be reviewed by a senior officer.