PHOTOS | Jeremy Mayfield in court

CHARLOTTE, N.C. -- Race car driver Jeremy Mayfield is suing NASCAR, claiming defamation and breach of contract in connection with his suspension due to a random drug test result.

For the first time in court Friday, NASCAR officials revealed that Mayfield tested positive for amphetamines.

Mayfield's attorney, Bill Diehl, filed several motions, accusing NASCAR of unfair trade practices, negligence, defamation, breach of contract and breach of the Persons with Disabilities Act. Mayfield has said in the past that he has attention deficit hyperactivity disorder.

The lawsuit names NASCAR and Aegis Sciences Corp. -- the company conducted the random drug test.

Mayfield was suspended from racing on May 9. Mayfield said he used the prescription drug Adderall to treat the ADHD and he took Claritin-D to treat allergies.

NASCAR says that combination couldn't cause a positive test.

Mayfield is seeking punitive damages and an injunction that will allow him to race and force NASCAR to stop talking about the drug test.

Diehl said in court that NASCAR's testing is erroneous, and NASCAR didn't give Mayfield a chance to disprove the test results.

"If you've got rules you're supposed to follow the rules and they didn't follow their rules," Diehl said. "What today they said was there's some rules that nobody knows about."

NASCAR officials urged the judge against making a hasty decision, saying they cannot let a driver on the track who tested positive for banned substances out of concern for other drivers and fans.

"NASCAR has followed NASCAR's policy," said NASCAR attorney Paul Hendrick. "There is no question that what sobriety and drug-free drivers on the racetrack are what NASCAR wants."

The judge denied Mayfield's request to return to racing, but he did issue a gag order, saying NASCAR could no longer discuss the drug test publicly. The next court hearing is scheduled June 3.