Just £200 for a gun in London

He adds that prices are tumbling because gangs have been importing huge numbers of weapons as they become ever more ruthless.

An astonishing 600 guns are being recovered by police every year, but they admit this might be a fraction of the true number on the streets. For a little extra cash, criminals can even get hold of the fearsome Uzi sub-machinegun.

Sir John says there is clear evidence that gun gangs are spreading across London whereas a few years ago they were confined to a handful of boroughs such as Lambeth, Hackney and Brent. Now police officers are being stationed in countries such as Romania to provide intelligence on drug and gun-smuggling routes into Britain.

The Commissioner spoke out in an interview with the Evening Standard after a fortnight of escalating violence in which estate agent Tim Robinson was murdered outside his Battersea home and a gangster was left dead outside a police station in a bullet-riddled car.

He also announced that an extra 50 detectives are to be redeployed to fight gun crime in the capital. Thirty officers will be seconded to Operation Trident, the unit which deals with black-on-black shootings, while the other 20 will work within the Serious and Organised Crime Group targeting other gun-carrying criminals.

Sir John said: "We have to stem the large number of guns coming in. We know you can buy a gun in London for £200 to £300 now, and that's a frightening situation. The price of hiring or buying a gun has come down because there are more guns circulating. We are having success, we are taking out about 600 guns a year, but that's going up, it's escalating. "

He said some of the weapons were " fearsome" Uzi sub-machine guns, a favourite weapon of the Yardie gangster.

"We have a real problem with the importation of guns and I want to improve our relationship with some of these countries such as the former Eastern Bloc and Jamaica so we have proper intelligence to stop these people coming in not just with guns but with drugs.

"The other frightening thing is that some people are converting guns for proper use. One factory in north London was found in an ordinary house." His warning comes as figures revealed that the number of firearm incidents involving Yardie-style gangsters in London had risen by 133 per cent in January compared with the same month in 2000, with police investigating four gun murders and 25 shootings.

There were 38 firearms murders in London last year, a 52per cent increase on the previous year. A total of 21 of these involved black-on black murders while there were 135 non- fatal shootings.

Sir John said the decision to arm London's police was constantly under review and praised the "exceptional bravery" of unarmed officers tackling armed criminals daily.

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