Francisco Rodriguez has failed a drug test after inflicting a first professional defeat on Olympic gold medallist Galal Yafai.
Yafai's nine-fight unbeaten record was ended by a punishing unanimous decision loss as he was cut, hurt and floored by Rodriguez in front of his hometown fans in Birmingham earlier this month.
The defeat severely dented Yafai's world title hopes as the WBC interim flyweight belt was at stake, but it has subsequently emerged that his Mexican opponent returned an adverse finding in a drug test.
Promoters Matchroom, which staged the bout, said in a statement: "Today, the Voluntary Anti-Doping Association informed Matchroom, the World Boxing Council and the British Boxing Board of Control that Francisco Rodriguez has returned an adverse analytical finding as part of a post-fight night anti-doping test following his bout with Galal Yafai on June 21 2025."
Sky Sports has contacted Matchroom to find out if they could appeal for the result to be changed to a 'no contest'.
Yafai, who dominated his opposition when winning Olympic gold in electric style at the Tokyo Games in 2021, is renowned for his workrate and power.
But Rodriguez beat him at his own game, repeatedly hurting Yafai and dropping him in the 12th round at bp pulse LIVE Arena.