THE idea that a North-East engine manufacturer was experimenting with sheep urine in an attempt to help the environment seemed, quite simply, baa-king mad.

But Darlington-based Cummins' unusual efforts to reduce harmful emissions of nitrous oxide from buses still managed to send the world's media into a frenzy.

The story - that buses were to be fitted with tanks containing sheep urine, which would be injected into exhaust fumes - made headlines across the globe earlier this month.

Newspapers, TV channels, radio stations and trade journals in Britain, the US, Africa, Australia, China, Bahrain, France and Holland revelled in telling the astonishing tale, as did The Northern Echo. But those who published and broadcast the bizarre news were last night told: "The joke's on ewe."

Cummins marketing manager Steve Mendick said: "It's been quite a good PR story, but unfortunately it's not true. One of the blokes from Stagecoach had jokingly said that this thing could run on sheep's urine and all of a sudden it was taken as gospel."

The novel system was said to have been taken up by Stagecoach and tested on buses in Hampshire.

Stagecoach South managing director Andrew Dyer even went so far as to tell a major transport conference in Birmingham that the new method could be the key to cleaner vehicles in the future.

However, while Cummins and Stagecoach are working on systems that feature the very latest in green technology, sheep urine will certainly not be a part of them.

A Stagecoach spokesman said: "We have always said that it is a synthetic urea that is being used.

"We were asked whether you could use actual urea from sheep and you could do that, but there is not a viable commercial process to produce it."