Nate Diaz investigated by Usada over possible UFC anti-doping violation after smoking vape pipe in press conference

Diaz was seen smoking a vape pen that contained a substance similar to medical marijuana

Nate Diaz may have landed himself in trouble with the United States Anti-Doping Agency (Usada) by smoking a vape pen containing oil similar to medical marijuana during his post-fight press conference.

Diaz suffered a majority decision defeat by Conor McGregor at UFC 202 on Saturday night, and he utilised his chance to speak to the media immediately afterwards to insist that he should have been awarded the victory in a fight that went the full five-round distance.

Yet it was his use of a vape pen that has triggered a Usada investigation that could see his UFC 202 misery grow even worse. Diaz was asked at the time what was in the pen, with the Stockton fighter revealing that it was a substance called CBD oil, a pain relief product that has similar properties to medical marijuana used to help ease physical pain and trauma.

Cannabinoids are included on Usada’s banned substance list during in-competition timescales, which includes six hours before any fight and, crucially, six hours after. Given that Diaz’s press conference took place immediately after the bout, the 31-year-old could find himself in trouble and facing a suspension.

Diaz explained he was smoking the vape pen as it “helps with the healing process and inflammation.” However, a difference in the rules and regulations employed by Usada and the Nevada Athletic Commission may have left Diaz unaware on any potential indiscretion.

The Nevada State Commission rules that the in-competition period expires once the final post-fight sample has been given, but Usada’s agreement with the UFC states that a six-hour limit after a fight is enforced before the in-competition phase expires.

Usada have confirmed that they are investigating the matter, and given that Diaz openly explained the details of the substance inside the vape pen, the American could be bang to rights should any charge materialise.

“I can confirm that Usada is aware of the situation and is currently gathering information in order to determine the appropriate next steps,” Usada spokesman Ryan Madden told ESPN on Monday.