Police arrested four men suspected of brandishing a gun at tennis star Andy Murray - but later realised they were autograph hunters with a tennis racquet.
The mix up occurred in north London on Wednesday night when the Scot was in a car with his agent.
It is understood that two men got out of another car and knocked on the window of Murray's vehicle in an attempt to get him to sign a racquet, but the Wimbledon champion drove away.
Things went from bad to worse for the men as a member of the public thought one of them was carrying a gun and contacted police.
A Scotland Yard spokesman said they received a call at 5pm on Wednesday to report a sighting of a man with a firearm in a Mercedes car in Avenue Road, Swiss Cottage.
The car was stopped in Tadema Road in Chelsea, west London and four men - aged 21, 26, 27 and 31 - were arrested on suspicion of possessing a firearm and taken into custody.
They were later bailed until late January pending further inquiries.
The spokesman added: "A search of the car was conducted and no trace of a firearm was found."
Murray is currently recovering from back surgery.