A fraud detective was given a suspended jail sentence after admitting conning his credit card company.
Lloyd Strang, 36, said £6,800 had been stolen from his card - but later confessed he told a friend his PIN.
Strang, of Penyston Road, Maidenhead, Berkshire, pleaded guilty to fraud at the Old Bailey in November last year.
He worked at the Metropolitan Police's financial investigations unit in Acton, west London, but was told by the judge that he is now likely to lose his job.
The detective constable was given a three-month jail sentence suspended for 12 months with a condition of 240 hours of unpaid work.
'Moment of madness'
Strang had worked for the force for 12 years and had been commended by the courts and senior officers, the court heard.
Det Insp Carolyn Davies said in one incident he had chased after a robber who fired a number of shots at him.
Richard Wormald, defending Strang, said he had lied "in the hope that he would avoid the debt".
Mr Wormald said the friend had gone to South Africa and added: "It was a moment of madness."
But Judge Paul Worsley told Strang: "You were a financial investigator and you must have known to be honest and diligent in all your dealings.
"You were under an obligation to see that your activities were above board and scrupulously honest."