Lost : Maddie McCann disappeared in Portugal eight years ago . Police chiefs have been urged to wind up the hunt for Madeleine McCann as detectives battle the terror threat and a spate of murders . A team of 31 British detectives are working exclusively to find the girl , who vanished from her parents ’ holiday apartment in Portugal eight years ago . The Metropolitan Police was tasked with investigating the disappearance after her family made a personal plea to David Cameron in 2011 . Yet despite costing the taxpayer £10million and dozens of trips by officers to the Algarve , the inquiry – codenamed Operation Grange – has not led to a single arrest . Now a senior police union leader has called for the probe to be axed and the detectives reassigned to other investigations in the UK . He says officers in London are bemused why they are working round-the-clock fighting the threat from Islamic State-inspired jihadists and solve at least 14 murders since Christmas while the Operation Grange detectives are barred from helping . Metropolitan Police Federation chairman John Tully said : ‘ It is time to re-focus on what we need to do to keep London safe . We no longer have the resources to conduct specialist inquiries all over the world which have nothing to do with London . ’ The Met has long been seen as the last resort for investigations others have struggled with elsewhere . ‘ It is surprising to see an inquiry like the McCann investigation ring-fenced . I have heard a few rumblings of discontent about it from lots of sources . ‘ When the force is facing a spike in murder investigations it is not surprising there is resentment of significant resources diverted to a case that has no apparent connection with London. ’ Even though Madeleine ’ s parents Kate , 47 , and Gerry , 46 , live in Rothley , Leicestershire , Scotland Yard was handed the investigation because of its expertise in investigating complex murder case . Police chiefs ‘ ring-fenced ’ the inquiry to prevent officers working on other case , even though the force has been forced to make £600million in cuts over four years . Operation Grange was set up to review the original Portuguese police probe into the disappearance of Madeleine , then three , from the family ’ s holiday apartment in Praia da Luz on May 3 , 2007 . The Metropolitan Police launched an investigation into Maddie 's disappearance after her parents , pictured above , made a personal plea to PM David Cameron in 2011 . After the Portuguese inquiry was shelved as ‘ unsolved ’ , the McCanns , who remain convinced their daughter is alive , appealed to Mr Cameron for assistance . Since the girl , who would now be 11 , vanished , every possible theory has been explored , including that she was kidnapped by a paedophile , killed during a botched burglary and her body dumped , snatched by traffickers and sold to a childless couple and that she wandered out of the apartment and died in a tragic accident . However , not one shred of proof of what happened to Madeleine has been uncovered . Detective Chief Inspector Nicola Wall , who took over Operation Grange in December , and her team ravelled to Portugal to interview seven suspects and four witnesses , but have not released any information about what they discovered . A Met Police spokesman said : ‘ There are 31 officers working on Operation Grange . Their sole investigation is the disappearance of Madeleine McCann . ’
A team of 31 British detectives working to find Madeleine McCann . David Cameron vanished from Portugal holiday apartment eight years ago . Metropolitan Police tasked with investigating by Maddie . Operation Grange has cost the taxpayer £10million since 2011 . Not led to a single arrest and now facing calls for it to be axed .