He has been a thorn in the side of the scientific establishment with his outspoken views on BSE and has been told by the Government's Medical Research Council (MRC) that independent scientists have been unable to approve his alleged test because he could not respond to "practical difficulties" with its use.
The MRC said yesterday that the problems arose last year and it had given Dr Narang an extra nine months to find a way to overcome the difficulties of validating the first phase of the two-phase project to get the test to work in a clinical setting using the urine of people suspected of suffering from new variant CJD - the human form of BSE.
Dr Narang had access to a specially built electron microscopy laboratory and several researchers at the University of Leeds to prove that his test really worked.
Experts from the National CJD Surveillance Centre in Edinburgh co-ordinated the supply of urine samples from patients.
But the project did not get beyond the first phase, costing pounds 125,000 and expected to last only six months, because of problems with contamination. Dr Narang's test used distilled water that had not been filtered, so enabling bacterial strands to contaminate samples and so be confused with the microscopic fibres he believed indicated a positive result for BSE or CJD.
The MRC said that Dr Narang has been given every opportunity to respond to the criticisms of his scientific protocol but he has declined, bringing the work to an end before the second phase of the 18-month project could begin.
George Radda, the secretary of the MRC, said that without proper validation that could be open to scrutiny by independent scientists, the technique of Dr Narang could not be considered a viable test.
"The present evaluation has not succeeded. In the judgement of the scientists at Leeds university, everything possible has been done that could have been done by the MRC," Dr Radda said.
A test for BSE would provide enormous benefits both for farmers and doctors concerned about the spread of new variant CJD in the human population. Dr Narang has repeatedly claimed that he has developed an accurate diagnostic but had been prevented from validating it by government officials.
"I already had a diagnostic test for BSE which I had developed for [sheep] scrapie in 1985 and 1986 and published in 1987," Dr Narang told the inquiry into BSE.
If the test has been developed early in the BSE epidemic, diseased animals could have been eliminated from the human food chain, Dr Narang said.
Dr Narang has already received tens of thousand of pounds of public money to develop another version of his BSE test, with the help of scientists at the London Hospital - but this ended in failure, as well.
Dr Narang was suspended from this post as a clinical microbiologist at the Public Health Service Laboratory in Newcastle upon Tyne because of allegations of misconduct. He was later made redundant.
1 That he discovered an unusual form of CJD at the end of the 1980s which he believed was caused by BSE. In fact, the new variant form of CJD was only discovered at the end of 1995 and confirmed as totally new in 1996. Its links with BSE were only established after experiments on mice were published in 1998.
2 He claimed in 1997 he could prove that chickens can be infected with BSE, although he insisted on keeping the carcasses of the hens to himself until he could finish his research. No published research has ever established that chickens can be infected with BSE.
3 In 1996 Dr Narang cast doubt on tests that were supposed to give milk a clean bill of health for being BSE-free. However, there is no direct evidence that milk can pass on the BSE agent.
4 Dr Narang claims that BSE is caused by a new type of virus containing genetic material known as nucleic acid. He claims to have identified the nucleic acid but most other scientists believe that a virus is not the cause of BSE. As yet, his results have not been replicated.
5 Blood transfusions can transmit CJD and the human form of BSE. No evidence that they can has emerged but government advisers have taken precautions against it being passed on in white blood cells.