Consumers are being warned not to rely on new-style MOT certificates when buying cars.

The warning comes from the Trading Standards Institute (TSI) after a 38-year-old man in Cleveland was arrested on suspicion of forging MOT certificates with intent to deceive.

TSI is concerned motorists still do not know paper certificates are no longer proof of existence of a valid MOT. This is despite the new style certificates being in operation for nearly 12 months.

Motor trade lead officer at TSI, Gerald Taylor, said the new certificates are easy to reproduce causing trading standards and the police great concern.

"When the new certificates were first implemented in October 2011 they were only intended to be a receipt for the MOT," said Taylor.

"The downloaded certificate in its present form can be altered and abused at will using the simplest of computer software available with nearly every personal computer.

"Purchasers – whether private or trade - should not rely on printed MOT certificates when buying cars.

"There is also the possibility that unscrupulous traders, and service and repair outlets, could agree to MOT a vehicle and charge accordingly but not carry out the test at all – the prospective purchaser would be none the wiser unless they go online."

Chris Mason, managing director of Motor Codes, the industry standards body, exclusively told Autoblog car buyers should be checking whether a car has a valid MOT online.

"The new style MOT system hasn't quite been in place a year and we're all still used to having our bit of paper that shows a car as having a valid MOT," said Mason.

"It's a case of getting used to this different but very secure and easily checkable online process.

"VOSA's free, online verification facility makes it simple to get a clear-cut answer on whether or not a car has a valid MOT certificate and should form part of our routine checks when buying a car – just as we would look for outstanding finance and insurance write-off history."

Paul Everitt, SMMT chief executive, told Autoblog: "Motorists should always exercise caution when buying a used car as there is always a risk that unlawful individuals may tamper with vehicles or documentation for their own gain.

"The safest way to buy a second hand car is through a franchised dealer, but carrying out a vehicle history check and using government's online MOT checking tool are additional ways that motorists can protect themselves."