Dr Stephen Dealler, who now works at Burnley General Hospital, said that during a visit to the Neuropathogenesis Unit in Edinburgh in 1990 he was told by the scientists doing the experiment - Hugh Fraser and Moira Bruce - that the process of injecting ground-up tissues from cattle into mouse brains, to see whether they developed bovine spongiform encephalopathy (BSE), was inadequate.
It was a view he shared himself, he told the panel: "They were inoculating mice with BSE-infected tissues. But Maff [Ministry of Agriculture, Fisheries and Food] didn't know what sensitivity mice had to BSE. So what results came out would be inadequate to say whether tissue such as muscle was infective or not."
Both Mr Fraser and Ms Bruce expressed worries to him over the risk posed by such tissues to people eating cattle-derived food.
But Dr Dealler told the inquiry, led by Lord Justice Phillips, that his experiences at the University of Leeds, where he worked in the 1980s, showed him that it was next to impossible to persuade Maff to admit publicly that it was misinformed about the risks posed by food. He had worked with Professor Richard Lacey, who had tried to alert people to the dangers posed by salmonella, listeria and the possible failure of cooking methods using microwave ovens.
Subsequently, research has shown that the "mouse model" of infectivity used by Maff in the NPU experiments underestimates the infectivity of tissues by a factor of about 1,000. Meanwhile, in a separate experiment concluded last year, Dr Bruce showed that BSE was the cause of "new variant" Creutzfeldt-Jakob Disease (v-CJD) in humans. So far, 24 Britons have died of v-CJD.
Dr Dealler was one of the first independent scientists to point out many of the aspects of the epidemic which have subsequently been confirmed by others. In 1992, in spite of refusal by Maff to provide detailed data, he calculated that many more cattle incubating the disease were passing into human food than ever fell ill. He worked out that the ratio was 7 to 1. In 1995, Professor Roy Anderson of Oxford University, using Maff's full database, showed that the ratio was 6 to 1.
In 1994, Dr Dealler warned that blood transfusions might be a possible source of infection of v-CJD between people. But government sources resisted the suggestion. Late last year, the Government admitted that blood products could be infected with v-CJD, and withdrew a number of supplies.
The inquiry should examine the theory that organophosphates (OPs) cause both BSE and v-CJD, an all-party group of MPs said yesterday. The chairman, Paul Tyler, Liberal Democrat MP for Cornwall North, said it was "too much of a coincidence" that OP farm use and BSE had coincided so closely.Reuse content