Suspended owner/driver Jeremy Mayfield denies he has taken methamphetamines and says because NASCAR has indefinitely suspended him for a failed drug test he has lost the sponsorship of his racecar and had to lay off ten employees, according to documents filed in US District Court on Thursday.

Mayfield and NASCAR filed several documents Thursday in preparation for a hearing next Wednesday on Mayfield's request for a preliminary injunction to stop NASCAR from enforcing the suspension, reported Thursday.

Mayfield was tested May 1 and suspended May 9. He filed a lawsuit against NASCAR on May 29, and NASCAR countersued him June 5.

Mayfield claims a combination of Claritin-D taken for allergies and the prescription drug Adderall, taken for attention-deficit-hyperactivity disorder resulted in a false positive determination by Aegis Laboratories, which conducts the NASCAR testing programme.

NASCAR claims Mayfield had an additional illegal drug in his system, which it has not identified, but Mayfield indicated in an affidavit filed that he was suspected of having used methamphetamine.

"I have never taken methamphetamines in my life, and when accused of taking them, I immediately volunteered to give another urine sample," Mayfield states in an affidavit that accompanies his brief in support of the injunction request. "Aegis refused my offer. ... The Aegis drug test was erroneous. Their actions and those of NASCAR have eliminated my ability to show the test results were a 'false positive'."

Mayfield's motion indicated he would attempt to make the July 4 race at Daytona International Speedway if he obtains the injunction Wednesday.

"Mayfield has already been publicly accused, tried and convicted by NASCAR, even though he has done nothing wrong," Mayfield's motion states. "As a result, Mayfield and his race team have lost, and will continue to lose, crucial advertising, sponsorship, and business opportunities. ... (His) sponsor now refuses to honour its commitments.

"Smaller corporate sponsors that Mayfield worked with successfully in the past will no longer do business with him either."

In its filing, NASCAR includes affidavits from drivers Jeff Gordon, Jimmie Johnson and Robby Gordon stating they are not 'willing to put my life at risk driving a racecar on a NASCAR track with drivers testing positive for drugs that diminish their capacity to drive a racecar'.

"If NASCAR is forced to allow a drug user to race in its events, such driver may cause serious injuries, including fatalities, to NASCAR's fans," NASCAR vice president of racing operations Steve O'Donnell said in an affidavit. "It would take a simple lapse of judgment by a driver under the influence of a banned substance to create a catastrophic accident."