WADA told Munguia's team about the failed test on Wednesday night. The Mexican boxer now has 10 days to ask for a second test of his B sample. If the B sample also comes back positive, Munguia could lose his victory and face a suspension of six months to a year.
Munguia took to Instagram to defend himself. He said:
"I am surprised like everyone else. I am a clean athlete. I am willing to take all the necessary tests."
His team is working on a formal response and plans to request analysis of the B sample.
Bruno Surace, Munguia's opponent in the May 4 fight, isn't buying it. He told The Ring:
"There is no place for cheating in boxing. The sport is dangerous enough. I knew he couldn't beat me on a level playing field. I am confident that the result of the fight will be reversed immediately."
This isn't the first time a boxer has faced this kind of problem. Ryan Garcia dealt with a similar situation last year.
The news has sparked criticism on social media, with many pointing fingers at Canelo Alvarez's team, especially Eddy Reynoso. Some fans think it's more than just a coincidence that another fighter associated with Reynoso has failed a drug test.
Golden Boy Promotions, Munguia's promoter, hasn't made any official statement about the situation yet.
As the story unfolds, boxing fans will keep a close eye on the results of the B sample test and any decisions made by boxing authorities.