LAS VEGAS >> A Nevada judge is upholding a fine and yearlong suspension for Ultimate Fighting Championship competitor Nick Diaz after he tested positive for marijuana use last year.

A court order made public Wednesday shoots down Diaz’s challenge that he had a prescription from a doctor in California to use medicinal marijuana to treat attention deficit hyperactivity disorder.

The court ruling says there’s substantial evidence Diaz broke rules by using the substance before his Feb. 4, 2012, UFC welterweight title loss to Carlos Condit.

It adds that Diaz likely understood he should have disclosed the pot use before the fight, and says the Nevada Athletic Commission didn’t overstep its bounds by suspending him.

Diaz was fined $79,500 and banned from fighting until February 2013 following the violation.