NASCAR CEO Brian France has labelled Jeremy Mayfield's violation of their substance abuse policy a 'serious' one, but would not reveal the drug for which the driver tested positive.
Last weekend Mayfield was suspended indefinitely from NASCAR after results of a random test from the previous week at Richmond International Raceway were positive both for an A and a B sample.
Mayfield said last week in a statement that the positive result may have come as a consequence of him combining some prescribed and over-the-counter drugs, but NASCAR's Dr. David Black ruled out that being the case, saying Mayfield had tested positive for a "drug of concern."
Speaking at Lowe's Motor Speedway, Brian France backed Dr. Black's view, saying Mayfield's was a serious violation.
"What we have said, and I'll say it now, last weekend we had a serious violation of our test, of our substance abuse policy, which gets you in our situation an automatic and indefinite suspension," said France.
"That is where we stand with Jeremy today. We've been down this road with other infractions of our policy in the past. We said it's serious. The process going forward is a process.
"It's not just NASCAR says or the laboratory says. You tested positive. That would obviously be true."
NASCAR officials have remained tightlipped on revealing the drug found in Mayfield's two samples. When asked about it, France was also reluctant to go any further citing privacy issues.
However, he said that drivers and crew members using drugs for medical reasons can consult NASCAR's liaison and even in the case of a positive result in a test, they would be treated in a different way than those testing positive for a recreational or performance-enhancing drug, as was Mayfield's case and that of others in the past.
"If you fall into the [recreational or performance-enhancing drug] category, as we said, a serious infraction, which a number of people have, in either one of the areas of performance-enhancing or recreational, at levels that Dr. Black believes violate the policy, that's the end of the road at that point," France said.
"They'll be notified and the process will then begin, as it has for Jeremy, other crew members, other drivers, as I described today."
In the wake of Mayfield's positive, some NASCAR drivers have already voiced their concern about 'false positives' emerging from the use of prescribed medicines. Four-time champion Jeff Gordon was one of them, but said that it's up to the drivers and crew members to work with NASCAR in order to avoid that.
"I definitely have heard guys talking about what about this prescription or what about this over-the-counter, it's really about what can create sort of a false positive," said Gordon.
"It's our job to work with our doctors as well as work with Dr. Black and some of the liaisons to make sure they know like I have bad allergies so I take Allegra every day. It's important for us to share all of that information with them."
Mayfield has been the first driver to test positive under NASCAR's new substance abuse policy, which includes random tests on every race weekend.
At least four crew members have already been suspended as well during the year for testing positive, including one working for Mayfield's team during the Daytona 500.