The 26-year-old Mexican fighter tested positive for marijuana in September after his first professional loss.
At a meeting Tuesday, commissioners asked why Chavez had not yet returned to Nevada for disciplinary action.
Chavez could receive a lengthy suspension or a significant fine on his $3 million purse.
Chavez (46-1-1) has already been suspended once, for testing positive for a diuretic in 2009.
His promoter, Bob Arum, said in September that he did not see marijuana as a performance-enhancing drug.
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