BMW has begun contacting its large corporate clients to remedy security failings which have left some of its vehicles susceptible to theft.

While Audi said it is investigating whether any of its cars could be affected and will act quickly if there is any risk.

Fleet News reports that BMW began approaching fleet managers last week after owners found that certain models were being stolen using “hi-tech” methods.

Gangs of organised criminals are breaking into the cars before cloning their wireless key fobs using specialist electronic devices called OBD programmers.

These reprogram blank keys after accessing information from a vehicle’s on-board diagnostics (OBD) port. The issue affects a number of manufacturers’ models.

BMW has stated that all models built after September 2011 and new 1 Series Hatch, 3, 5, 6 and 7 Series vehicles cannot be stolen using this method.

It is now encouraging fleet managers who believe that they are affected to contact its customer services department directly so that the security of their vehicles can be enhanced if necessary.

A BMW spokesman told Fleet News: “From working with the police and other authorities, BMW is aware that some of its products, along with those of other manufacturers, have been the subject of unwanted attention by professional criminals.

“A detailed investigation has revealed that certain BMW models in particular have been targeted.

“Following extensive testing we are now in the process of taking steps to mitigate against a type of forced entry vehicle theft on BMW X5 and X6 models, which seem to be the focus of organised criminals.

“Similar measures for other models will be available from eight weeks’ time. For security reasons we cannot say what measures are being undertaken.

“It is important to note that BMW Group products still meet or exceed all global legislative criteria concerning vehicle security.

“This is a free-of-charge, extraneous action as part of a continuous evolution and improvement process of our products for the added benefit and peace of mind of owners.

“It has only been made possible by extensive testing of vehicles in the market over several months.”

The most recent car crime figures collated by the Office for National Statistics show that reported incidents of car theft fell from 106,162 in the 12 months to the end of March 2011 to 92,057 in the corresponding period this year.

But these figures do not reveal either the makes and models of vehicles which are most frequently stolen or the methods used to steal those cars.

Ian Wallace, from Thatcham – which works with manufacturers to influence the safety and security of new vehicles – said: “The police made us aware of this issue several months ago.

“We are still looking at the issue and our work with manufacturers is ongoing at the moment.

“It’s not only BMW that has been affected. As a general rule, if a vehicle has a diagnostic port then it will potentially be vulnerable.”

An Audi UK spokesman confirmed that the company was investigating its vehicles’ “keyless-go” security.

He said: “The safety and security performance of Audi vehicles is always of paramount importance to the brand and we take any potential breach of either exceptionally seriously.

“We are aware of media coverage of vehicles fitted with keyless-go starting systems and their alleged increased vulnerability to theft.

“The claims made will understandably cause concern and we want to reassure Audi owners using this system that we are working with the relevant authorities to fully investigate them.

“We will act quickly and decisively if our results indicate that there is any risk whatsoever to the integrity of their cars.”

A spokesman for Mercedes-Benz said “highly robust” mechanisms meant that its vehicles’ keys could not be cloned using an OBD port.

He said: “An owner with lost keys needs to present documents proving legal ownership of that vehicle to an authorised dealership before their specific key code is accessed at the manufacturing plant in Germany.

“This code is then given to a named employee at Mercedes-Benz UK headquarters, in Milton Keynes, who cuts the new keys for both passenger and commercial vehicles.”