A former police chief has called for the investigation into the disappearance of Madeleine McCann to be wound up. Ex head of the Metropolitan Police’s Flying Squad, John O’Connor, has questioned whether probe should continue after it was revealed Scotland Yard has spent £11million on the case but have made no arrests. The Metropolitan Police was tasked with investigating the disappearance after Madeleine’s family made a personal plea to David Cameron in 2011. A team of 31 British detectives are working exclusively to find the girl, who vanished from her parents’ holiday apartment in Praia da Luz, Portugal eight years ago, with the enquiry codenamed Operation Grange. Now, according to the Sun, the Met’s enquiry into Madeleine’s disappearance has cost £11million, with money spent on flights to Portugal, salaries, overtime and premises expenses but no arrests have been made. They also report that if spending on the case continues at the current rate, the bill will top £12million by April – more than double the £5million promised by David Cameron when Operation Grange launched in 201