THE scientific blunder which scuppered years of research into BSE in sheep has been described as "incredible" by the president of the Malvern-based National Sheep Association.

John Thorley said he was stunned to find scientists had been testing cow's brains instead of sheep's brains by mistake for four years.

Last month, when the results indicated that the "sheep" brains tested positive for BSE, the Government said a slaughter of Britain's entire flock might be necessary.

Mr Thorley said the mistake had only been discovered following pressure from industry groups, including the NSA.

"This is absolutely extraordinary," he said. "I find it absolutely amazing that they undertake work over four years and then find it's the wrong material.

"It's a joke, but one that is in very poor taste. Sheep farmers have been on tenterhooks waiting to hear about this research."

Mr Thorley said independent research was casting doubt on the idea that BSE had jumped from cattle to sheep and he himself was convinced there was no contamination.

"It brings into question the validity of the science and of the management of the science," he said.

"Because we were concerned that the research was not of a good standard, the industry raised questions, which led to this blunder coming to light.

"When you consider the research was supposed to be scientific, and then you find out about something like this, you really wonder whether we are basing our future on a second-rate approach."

l Stunned by blunder: John Thorley.