The statement from the UFC comes a day after Diaz took to Twitter to emphatically denounce taking "tainted supplements" and announce his withdrawal from the headline fight against Jorge Masvidal.
UFC president Dana White took to Twitter early Saturday morning to clear Diaz's name and advertise the main event.
In its statement, the UFC revealed that Diaz ingested organic, vegan, plant-based daily multivitamins that were contaminated with LGD-4033, which resulted in a positive sample.
The statement went on to detail that under the organization's recently revised anti-doping policy, Diaz did not commit a violation and "has not been provisionally suspended and is not subject to any sanctions."
On October 24, 2019, Nate Diaz released a public statement regarding a recent out-of-competition test conducted by USADA. UFC has been notified by USADA that the out-of-competition test concluded that LGD-4033 was present in Mr. Diaz’s sample at an amount below the decision concentration level for this substance. USADA is reviewing the out-of-competition test as an atypical finding.
The UFC added that "there is unequivocally no appreciable performance-enhancing or therapeutic benefit from the significantly limited amount of LGD-4033 that may be present in his system, which is roughly 10,000 times lower than one LGD-4033 therapeutic dose."
Diaz (20-11) has yet to address the UFC's statement, but is cleared to face Masdival (34-13) for the "BMF" title in the main event of UFC 244 on Saturday, Nov. 2 as previously scheduled at Madison Square Garden in New York, N.Y.