Police arrested four men suspected of brandishing a gun at Andy Murray but later realised the group were just autograph hunters with a tennis racquet.
It is understood that two men got out of another car and knocked on the window of Murray's vehicle in north London on Wednesday night in an attempt to get the Wimbledon champion to sign a racquet, but he drove away.
A member of the public subsequently contacted police as they believed one of them was carrying a gun.
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 spokesman confirmed that a car was stopped in west London and four men - aged 21, 26, 27 and 31 - were arrested on suspicion of possessing a firearm and taken into custody.
Police confirmed that after a search of the car no trace of a firearm was found, and the four men were later bailed until January pending further inquiries.