TMZ Sports broke the story ... Jones was flagged for Turinabol -- a banned anabolic steroid. The results from Jones' B sample were made public Tuesday -- confirming the bad news for Jones. As a result, the California State Athletic Commission overturned Jones' victory and now has it ruled as a "no contest."
Cormier appeared on "UFC Tonight" and said he's already been contacted by Dana White ... who informed him that the belt will be returned to him.
"Once again, I'm the UFC champion," Cormier proclaimed.
As for Jones ... his UFC career is in serious jeopardy -- he could get hit with a 4-year ban.