But a new test, developed jointly by British and Norwegian laboratories, could show whether or not the testosterone in Mrs Modahl's body is being produced as a result of a medical condition, according to Dr David Cowan, head of the International Olympic Committee Drug Testing Laboratory.
Clyde Williams, Professor of Sports Science at Loughborough University of Technology, said women with raised levels of testosterone would normally be expected to show male physical characteristics, such as facial hair.
Scientists specialising in endocrinology have been baffled by the suggestion that Mrs Modahl could be suffering from a medical complaint that is responsible for the testosterone levels found in her samples. This was 40 times greater than normal. Mrs Modahl's case is currently under appeal. She faces an inquiry within 30 days.
Dr Cowan said the new test, which is technically ready to use but not yet available to athletes, should be on offer. 'This should be a facility made available to them, but I would not want to force it on them. It is up to sport to decide what it wants,' he told the British Association for the Advancement of Science.
The test is based on a drug called a ketoconazole, which blocks the production of testosterone by natural, biological routes in the body. An athlete would be tested before and after being given the drug. If his or her testosterone level fell, this would indicate that the hormone was being produced naturally, perhaps by a medical condition, such as a tumour. If the level stayed the same, then a medical condition would be unlikely to be the explanation.
'The test can be performed in six to eight hours with the athlete's agreement. It is another tool which will help an athlete to show their innocence,' Dr Cowan said.
He confirmed that some rare tumours can produce testosterone in both men and women, and was sceptical of the suggestion that the test might have been tampered with. He said Olympic testing laboratories were checked regularly to ensure that their testing procedures were being performed according to strict rules. 'Until we hear otherwise, I would go on the assumption that the laboratories do handle samples correctly.'
Dr Cowan was optimistic about blood tests being developed to complement urine tests. These would be useful for determining what was in a person's body, rather than just what had left it. He said that of the 4,000 tests from sports people carried out at his laboratory every year, only 1 per cent had adverse findings.
IAAF backs Britain, page 44Reuse content