A millionaire builder who was gunned down on the doorstep of his Earlsfield home was left undiscovered for four hours as police failed to pick up a 999 call, an inquest has heard.

Yesterday Westminster Coroners' Court was told how dad-of-two Stuart McMahon, 45, died in a hail of bullets at his Magdalen Road house at some time between 7pm on September 29, 2006 and 4.30am the following day.

Acting Detective Inspector David Kennett admitted that the four-hour delay was "unacceptable".

Mr McMahon died from gunshot wounds to the chest.

Coroner Paul Knapman recorded a verdict of unlawful killing.

Despite police offering a £20,000 reward to catch Mr McMahon's killer last year, no one has been arrested or charged for the murder.