Thatcham, the motor insurers' research centre, has strongly refuted claims by What Car? magazine that 70% of new cars are failing to meet Government standards on security.

The What Car? survey reports alarmingly that top-selling models such as the Peugeot 206, VW Lupo and Chrysler Neon can be broken into in less than two minutes.

The magazine for motor enthusiasts' also adds that 61 of the 85 new models it tested were broken into in less time than the two minutes allowed by the Home Office. The top performing models, in terms of security, were the Lexus IS200 and BMW 323.

But Thatcham considered the survey critically flawed because it used expert locksmiths to test the security systems of new cars.

Mark Inman, research manager in vehicle electronics at Thatcham, said: “The Government has laid down a maximum entry time of two minutes for new cars – which is fine for the average yob on the street, but not a difficult test for an expert locksmith.”

He added that older models, rather than newer cars, remain most vulnerable to attack by thieves.

“Car crime has actually fallen by 4% this year, and cars being taken are usually at least five years old.”

Inman went as far as to say that a new model could be stolen only by fraud or deception.

But the survey's findings are supported by vehicle navigation and detection systems company NavTrak, which said it proved alarms and immobilisers are an inadequate deterrent to thieves.

Giles Harridge, NavTrak spokesman, said: “It is still a very easy task for a determined thief to break into and drive away many of the newest cars on the road.”