BOXER Amir Khan was left reeling after a hammer-wielding maniac smashed up his £50,000 car.

The stranger confronted Amir, 22, in the street when he was picking up a takeaway from a restaurant.

Khan, carving out an explosive professional career after winning an Olympic silver medal, tried to ignore him.

But the boxer and his pals were stunned when the man returned with a hammer and laid into his white Range Rover Sport — caving in the rear windscreen and two side windows.

Last night an onlooker said: “It was really weird. This guy went up to Amir in the street and started staring at him.

“Then he said, ‘So, you think you’re a boxer — what are you going to do?’

“There was a bit of scuffling between him and Amir’s mates, and then another guy stepped in and broke it up.

“But a few moments later the bloke who had been eyeballing Amir returned with a hammer and ran towards the Range Rover. Then he suddenly started smashing the windows. It was like this fella was crazy.

there was no way anyone was going to try and stop him because he was swinging this hammer about.

“It all happened so fast. Then this bloke just ran off.

“Amir and his friends were left totally shocked.”

Amir took the car for repairs to a dealer near his home in Bolton, Greater Manchester.

Police confirmed they had attended the bust-up at 4.15pm on Christmas Eve.

A spokesman said: “Detectives are investigating an incident where a man was punched in the face, and are aware of reports that a car had its windows smashed. Our inquiries are ongoing.”

Khan, who began boxing competitively aged 11, soared to fame after winning a silver medal when he was just 17 at the Athens Olympics in 2004.

He had his first professional defeat in September this year — a shock first-round stoppage — but got his career back on track on December 7 with a two-round knockout.