A jealous undertaker stole keys from a hearse leaving a body locked inside forcing a rival businessman to hot-wire the car, a court has heard.
The coffin of Patricia Thorburn, who died in September 2008, was left stranded in a Rolls Royce after undertaker David Wood snatched the key.
Wood believed a rival had poached his customers. The 48-year-old of Bridge Court, Middlesbrough, admitted theft.
He will be sentenced next month at Teesside Crown Court.
The court was told how Wood was jealous of the success of Joel Kerr's rival funeral business, and stole the keys from the vehicle parked outside the Salvation Army citadel in Middlesbrough.
While Mrs Thorburn's friends and family waited to bury her, a queue of mourners waiting for the next funeral to begin, formed outside.
It had been her final wish to be transported in a vintage Phantom VI Rolls Royce, prosecutors told the court.
The stranded vehicle was too heavy to push and Mr Kerr was forced to rip out the dashboard from the 1968 car, and hot-wire the engine.
Irene Jessop, a funeral director with Joel D Kerr Undertakers, said: "The worst thing was that it was a funeral director that did it - a funeral director acting against another funeral director.
"It was a very sad thing to see. The family were extremely upset by it, but they were wonderful.
"They were very, very understanding. The sad thing is that the funeral of their mother and wife will always be remembered for the wrong reasons."
Wood was told he faces a community penalty and that he would have to pay Mr Kerr compensation.