Excuse is possible: chief chemist
The chief racing chemist responsible for carrying out the Jockey Club's drug-testing programme, Dr Terence Wan See-ming, admits it is plausible that the Ketamine positive returned by Kevin Leung Ka-wai could have been produced by a small amount of the drug ingested unknowingly.
Wan would not reveal the levels of Ketamine found in Leung's positive sample, but said that in theory it was possible the apprentice may not have realised he had inadvertently been exposed to a small amount of the drug.
'I am a chemist conducting the sample tests, and I cannot draw conclusions about whether the administration of the substance was deliberate or accidental. We only determine if the drug is present or not,' Wan said. 'There are all kinds of possibilities as to how the drug entered the system.
'Whenever we test a sample for any prohibited substance we are doing so in accordance with the rules of racing. If the rule stipulates that no amount of a particular substance is allowed in a sample, then we report to the stewards when it is present.
'Of course, we know how much of the substance is in the sample, but I cannot disclose these amounts unless it is at the stewards' direction,' Wan said.
During the 2009-10 season, the racing laboratory analysed 533 urine samples from licensed jockeys, including apprentices, on race days and after trackwork and barrier trials.
Each jockey licensed for the season was subjected to testing for prohibited substances, including alcohol, between 10 and 30 occasions. While a minimum of four jockeys are selected at any given race meeting, often every jockey is required to provide a sample.
'I will say that we are always mindful of the sensitivity of the tests and are not out to chase every last molecule of the sample,' Wan said.
'The body gets rid of substances at an exponential rate that gets more and more difficult to detect over time so, for example, to test for a drug taken three days ago may require a more sensitive analysis method than a test for a drug taken yesterday.'
Chief stipe Kim Kelly said the responsibility for being drug-free rested squarely on the jockey.
'Jockeys are professional athletes who have a responsibility to be free of substances which breach the rules of racing and they must be aware of the circumstances in which they place themselves at all times.
'While it would be inappropriate to comment on an individual case, the explanation proffered by persons appearing on matters involving prohibited substances frequently is one of inadvertent contamination by persons known or unknown.
'However, the evidence before the stewards in the vast majority of cases does not support such claims as there is generally a large amount of technical evidence available which, along with evidence obtained prior to and during the inquiry, enables the panel to form an opinion.'
During the 2009-10 season, the racing laboratory tested this many urine samples from licensed jockeys: 533