Despite warning signs on the fuel caps, members of the Metropolitan Police Service managed to put diesel into petrol vehicles or petrol into diesel vehicles on nearly 1,000 occasions between 2008 and 2013.
The expensive blunders, costing an average £290.76 to put right, have left vehicles useless until their fuel tanks are pumped out. The frequency of misfuelling at the Met is shown by figures released under the Freedom of Information Act.
Between 2012 and 2013 it cost the Met £47,909 for the 138 times it happened.