Five firefighters were injured when their fire engine crashed on its way to an emergency call in south-west London.

One crew member was trapped for 20 minutes inside the vehicle, which rolled on to its side as it careered around the Fountain Roundabout in New Malden last Monday morning.

Police launched an investigation to discover the exact cause of the accident, which caused traffic gridlock around the area.

It attracted dozens of onlookers with cameras, visiting the scene to witness the unusual occurrence an emergency vehicle a casualty of a road accident.

One witness, who did not want to be named, said: "I saw the fire engine coming from Burlington Road, and it was going really fast and had its sirens going. I turned away and the next thing I heard what sounded like a balloon popping and the fire engine was on its side."

Fire crews from as far away as Battersea were deployed to New Malden to rescue colleagues.

Among them was Surbiton station manager David Kennett who said the crew was coming from the fire station in Burlington Road and was heading around the roundabout when the engine "tipped".

He revealed that four firefighters got out of the fire engine after it crashed, all suffering bruises and shock. But one man was trapped.

Mr Kennett said it took about 20 minutes to release him from the engine and he was taken to Kingston Hospital with an arm injury. He said: "Considering what happened they were remarkably OK."

He did not know how fast the vehicle was travelling, but added: "The appliances are basically lorries, which means they cannot go as fast as police cars."

The New Malden firefighters were responding to an automatic fire alarm when the accident happened. A crew from Surbiton were also on its way to the call and dealt with it on their own.

No other cars or people were involved in the accident.

All five firefighters were released from hospital later the same day.

But Kingston and Surbiton MP Edward Davey said the accident raised a number of questions, which he hoped would be answered by the police investigation.

He said: "The investigation will clearly need to look at the issue of speeding and the issue of traffic flow on the roundabout itself."

There was more traffic misery for drivers on the way home on Monday when Hampton Court Road was closed between Kingston Bridge and Hampton Court Bridge because of a serious gas leak.