BUNGLING Suffolk police officers have cost the force more than �5,000 in two years – by using the wrong fuel.

Nearly one in eight of the force's fleet of diesel vehicles – more than 13 per cent – was filled with the wrong type of petrol between 2008/09 and 2009/10 at a total cost to the taxpayer of �5,778.

The figure was the fifth highest after the Metropolitan Police, Essex, Leicestershire and Warwickshire.

The figures, published in response to a Freedom of Information request, reveal that over the two-year period, 50 of Suffolk Constabulary's 374 diesel cars were damaged.

Each cost an average of �115 to repair, in labour, parts and recovery costs.

The figures also show that since 2007, 81 of the force's vehicles have been mis-fuelled at a cost of �10,301.

As a result, it has fitted special caps on vehicles to warn officers which fuel to use.

A Suffolk police spokesman said this had been a success: there were only eight mis-fueling incidents last year.

'Unfortunately even police officers and staff are prone to making mistakes such as this and it is down to human error,' said the spokesman. 'However, as the figures suggest, effective measures have been put in place by Suffolk Constabulary's transport services department to prevent this from occurring.

'Coloured caps and labels indicate which fuel should be used.'

The spokesman added: 'The disc has to be moved out of the way before the fuel cap can be removed and the fuel pump nozzle inserted. While the discs are not fool-proof they are a very low-cost preventative measure and have generally been effective in reducing the number of mis-fuelling. Furthermore, we also have a number of vehicles in our fleet which will not accept the incorrect nozzle when refuelling.'

Suffolk police were among 43 forces in England and Wales that responded to a Freedom of Information request for incidents in 2009 and 2010. The worst offending force, the Metropolitan Police, racked up a repair bill of �172,970 after almost one in six of its vehicles were filled up incorrectly.