A Carshalton man is counting the cost of the damage caused to his wife's Mercedes sports car this week after an unexploded firework came crashing through its roof.

Ian Watson was washing another of the family's cars when the wayward rocket pierced through the top of the £47,000 luxury cabriolet, missing him and some nearby children by just a few feet.

While one part of the rocket had gone off, the main section failed to detonate and instead of exploding at altitude it hurtled back down to Earth.

The 50-year-old engineer said: "I couldn't believe it, the car could have burst into flames and people could have been injured. It was lucky my bucket of water was conveniently to hand and so in it went."

Mr Watson is now fuming about having to pay £3,000 for repairs and for losing his no-claims bonus.

He said the rocket's manufacturers, Ripon based Bright Star Fireworks, should be liable for the repair bill.

"I'm not a spoilsport or an anti-firework campaigner, but I believe there has got to be some serious legislation where it can be shown that something has just fallen out of the sky. It's just ridiculous," he said.

A spokesman for Bright Star said that without full details of how the firework was launched and from where, it was difficult to comment on the incident.

He said if the instructions were followed on each firework, such incidents were improbable and it was likely whoever set the rocket off had either not complied with them or had deliberately misused the firework.

He added: "We can assure people that all products imported by Bright Star Fireworks are rigorously batch tested to ensure conformity to British Standards."