BRITISH police failed to spot a man had been murdered - until undertakers found a knife in his back, an inquest has been told.

Antoine Denis, 66, was found slumped on his back on his bedroom floor in Kent, southern England, in January this year after officers were called to his home by worried neighbours, Kent Online reported.

The father-of-four was pronounced dead at the scene but police did not think that a crime had been committed until the weapon and a stab wound were found by undertakers as they prepared to move his body.

Detective Constable Linda Robb told coroner Roger Sykes the knife was missed because it was dark in the flat and Denis was lying on his back.

Recording a verdict of unlawful killing, Sykes said Denis had died from a single stab wound, which penetrated his lung due to "the unlawful act of a person whose identity has not yet been established.”