BOMB disposal experts were called out to Owlerton Greyhound Stadium in Sheffield after workmen discovered an unexploded World War Two device.
The incendiary bomb was unearthed by a team of sign fitters as they dug holes in the stadium car park.
Unaware of the danger, the contractors loaded the bomb into the back of their van and drove it back to their head office for further inspection.
Once they recognised what the device was and realised the danger it posed, the sign fitters immediately called the police.
Images of the bomb were sent to the Army for analysis.
The disposal team later removed the bomb and carried out a controlled explosion.
John Gilburn, Owlerton’s managing director, said: “The bomb was discovered during some refurbishment work here at the stadium.
“It is thought to be from an armoured personnel carrier, although how it came to be in the stadium’s car park is still a mystery.”
Mr Gilburn also thanked the Army team, ‘for ensuring a safe disposal’.
Incendiary bombs were used extensively during World War Two.
They were designed to ignite on impact, starting fires intense enough to destroy buildings and equipment.