Mexican boxer Moises 'Taz' Calleros was hit with a four-year drugs ban before anti-doping chiefs discovered that he'd died three months ago.
Calleros passed away suddenly on March 1 at the age of 34. It was suspected that the fighter had suffered a cardiac arrest.
UK Anti-Doping appeared not to be aware of his passing when they confirmed that he'd tested positive for cocaine following his defeat to Britain's Galal Yafai last year. Calleros lost his bout at the O2 Arena in London on the undercard of Anthony Joshua's victory over Jermaine Franklin in April 2023.
Yafai, 31, claimed a fourth-round win via TKO in what was only his fourth professional fight. Subsequently, opponent Calleros has tested positive for the Class-A substance.
UKAD's initial statement on Monday read: "Mexican Professional Boxer Moises Calleros has been banned from all World Anti-Doping Code-compliant sport for four years, following Anti-Doping Rule Violations (ADRVs) for the Presence and Use of a Prohibited Substance.
Five things which definitely won't happen in fighting this year"Mr Calleros was tested by UK Anti-Doping (UKAD) on 1 April 2023 after his bout against Galal Yafai at the London O2 Arena. Analysis of his Sample revealed the presence of cocaine and its metabolite benzoylecgonine. Cocaine is prohibited In-Competition. It is also categorised as a 'Substance of Abuse' on the World Anti-Doping Agency's Prohibited List.
"UKAD notified and charged Mr Calleros with ADRVs for the Presence and Use of a Prohibited Substance and provisionally suspended him. The case was then later referred to the independent National Anti-Doping Panel (NADP) to determine whether the ADRVs were proved and, if so, the appropriate Consequences.
"The NADP concluded that Mr Calleros had committed both ADRVs and issued the boxer with a four-year ban from all World Anti-Doping Code-compliant sport. While shorter bans are available for athletes who can establish that cocaine use or ingestion took place Out-Of-Competition and in a context unrelated to sport, Mr Calleros did not put forward evidence to meet those requirements.
"Mr Calleros is entitled to credit for the time he spent provisionally suspended, so his ban is deemed to have commenced on 8 June 2023 and will end at midnight on 7 June 2027."
Replying to a social media post about the news, Yafai noted: "He passed away in March if you didn't know already! RIP."
After learning that 'Taz' had died, UKAD responded by saying: "UK Anti-Doping (UKAD) has today received information regarding the death of Mexican professional boxer Moises Calleros. UKAD received this information shortly after publishing details of the outcome from a case concerning Mr Calleros in accordance with the UK Anti-Doping Rules.
"Unfortunately, UKAD had no information regarding Mr Calleros' sad passing at the time of publication and has now removed all details of this case from its channels."
Calleros' first professional fight was in October 2008. The Mexican notably fought twice for the WBO interim minimum-weight title but lost both times.
His first defeat was to Japan's Tatsuya Fukuhara in February 2017 via split decision. A year later, 'Taz' lost to another Japanese fighter, Ryuya Yamanaka, after retiring in his corner. Following his last fight against Yafai, Calleros' professor record read 37-11-1. His penultimate loss was at the hands of WBC flyweight champion Julio Cesar Martinez in June 2021, as Calleros was stopped via TKO.
He then won his next three bouts before facing Yafai and bounced back from the London defeat when he fought Gerardo Verde in Ensenada, Mexico. Calleros claimed first-round knockout, the second of his career. He was found dead by his wife.
Five fights we absolutely don't want to see in 2023 from Tyson Fury to Jake Paul