Mark Hunt today filed a lawsuit in Nevada District Court against the UFC, Brock Lesnar, and Dana White.
ESPN's Brett Okamoto reported the story earlier tonight. It's a landmark case because Hunt is claiming that the defendants "affirmatively circumvented and obstructed fair competition for their own benefit."
Hunt had been threatening legal action, feeling that his career has been harmed by facing people who have cheated. Hunt was upset because he felt Lesnar was not punished enough for a failed drug test before their fight took place, and that he went into the cage without knowledge that Lesnar had already failed a test, as the result of a June 28th test didn't come back until after the July 9th fight.
The tough aspect of this case is that Lesnar failed for Hydroxy Clomiphene, and not for steroids or another PED. So while there are two failed tests, on June 28th and July 9th, there is no evidence that specifically ties Lesnar to PED usage for the Hunt fight.
Lesnar is currently serving a one-year suspension from UFC competition as well as within commission states that license pro fighters and wrestlers due to the positive tests.