John Riel Casimero has literally landed in hot water.

The three-division titlist is now at risk of being forced to vacate his WBO bantamweight title due to his use of a sauna days ahead of a scheduled title defense in Liverpool. Casimero was due to face mandatory challenger Paul Butler this Friday but is no longer permitted to go through with the fight after violating terms of the British Boxing Board of Control (BBBoC) medical guidelines. The BBBoC has a strict zero-tolerance policy regarding the use of saunas to lose weight before a fight.

“The British Boxing Board of Control has been made aware (with supporting evidence) that Mr. Casimero has made use of a sauna in close proximity to his World Boxing Organization Championship contest on 22nd April 2022 in Liverpool,” Robert Smith, general secretary of BBBoC stated in a letter to all involved parties for this weekend’s main event, a copy of which was obtained by BoxingScene.com. “As you are aware, this is against BBBoC’s medical guidelines and therefore we can’t permit him to compete in the proposed contest on Friday.”

Philippines’ Casimero (31-4, 21KOs) is now forced out of a planned title defense versus Butler for the second time in four months, and once again met with a Show Cause letter from the WBO to justify his avoid being stripped of the belt.

“Please be advised that on Tuesday, April 19, 2022, the WBO confirmed receipt of email correspondence from the British Boxing Board of Control (BBBofC) advising that supporting evidence was provided to the "BBBofC" regarding John Riel Casimero using a sauna in proximity to his scheduled WBO Bantamweight Mandatory Championship Contest against Paul Butler on Friday, April 22, 2022, at the Echo Arena, Liverpool, England, United Kingdom,” Luis Batista-Salas, chairman of WBO Championship Committee stated in a letter addressed to Egis Klimas, Casimero’s manager. “Per the British Boxing Board of Control, Casimero's actions are against the Board's medical guidelines and therefore, he will not be permitted to compete accordingly.

“Therefore, considering the foregoing determination by the "BBBofC," the relevant conditions stated in this Committee's "Resolutions," and the facts stated herein, Casimero is hereby ordered to "Show Cause" within the next 48 hours as to why the "WBO" Bantamweight Championship Title shall not be declared "Vacant."

Casimero was under the same obligation following his late withdrawal from a planned December 11 title defense versus Butler to have taken place in Dubai. The scheduled main event was canceled after Casimero was unable to make it to the pre-fight weigh-in after reportedly being hospitalized due to gastritis.

Sufficient medical proof was provided to the WBO, allowing Casimero to retain the bantamweight title he has held since a November 2019 third-round knockout of Zolani Tete in Birmingham, England. Just two title defenses have followed along with four canceled fights—including two with Butler who for the second time in four months has seen a bid to become a two-division titlist fall apart during fight week.

Of grave concern to the WBO is Casimero’s lack of commitment to the sanctioning body during his two-plus year title reign.

“[W]e must stress that Casimero has not fulfilled a mandatory title defense obligation since his title acquisition on November 30, 2019,” noted Batista-Salas. “In other words, 2 years and four (4) months have transpired without Casimero discharging his mandatory obligation and therefore, Casimero is in clear violation of the WBO Regulations of World Championship Contests.”

Casimero arrived in England late last week, reportedly well on track to making the bantamweight limit for his rescheduled fight with Butler (33-2, 15KOs).

There is a dispute over the amount of weight that the Filipino in the past few days. Weight checks conducted by the BBBoC allege that he has lost ten pounds since Saturday. A representative from Casimero’s team informed BoxingScene.com that his weight check as of Tuesday morning was 119.8—just 1.8 pounds above the bantamweight limit—according to the scale they have been using ahead of his attempted third title defense.

The BBBoC is investigating the matter, complete with requesting “the name of each member of Mr. Casimero’s team as their compliance in this matter may affect their permission to work in the U.K. in the future.”

Casimero has fought just twice since winning his third divisional title. His first defense after the pandemic, stopping Ghana’s Duke Micah in the third round of a September 2020 Showtime Pay-Per-View event. The fight came as an alternative to his previously scheduled April 2020 three-belt unification bout with WBA/IBF bantamweight champ and pound-for-pound entrant Naoya Inoue (22-0, 19KOs) in Las Vegas, which was canceled due to the initial wave of Covid-19 which shut down the U.S. boxing scene for nearly three months.

The fight never came back to the surface, though Casimero was in line for another unification clash.

The brash Filipino was set to face legendary countryman Nonito Donaire, a four-division champ who had just reclaimed the WBC bantamweight title last May 29 and was set to face Casimero on August 14 in Carson, California. The fight fell apart due to a very public dispute over drug testing protocol, which led Casimero back to original plans. His scheduled title defense with former lineal junior featherweight champion Guillermo Rigondeaux was back in play, with Casimero winning a decision in a virtually unwatchable 12-round fight last August.

Unless he can come up with a valid reason for his latest actions, that fight could have very well been the last for Casimero as a reigning WBO bantamweight titlist.

Meanwhile, Butler hopes to remain in contention for the fight.

BoxingScene.com has learned that Jonas Sultan—number-three in the WBO rankings—was made available on the show, as a potential replacement opponent for the main event. Butler-Sultan would have to come with the blessing of the WBO, which presumably could not be made official any earlier than at the end of the 48-hour period afforded for Casimero to clear his name.

Similar efforts were made to salvage Butler’s place atop the December 11 Probellum show in Dubai. Efforts to keep Butler on the show included a contingency plan in the form of a fight with Joseph Agbeko, who was on the undercard and prepared to step up for the makeshift interim title fight. Butler declined, preferring to just revisit plans for his due shot at Casimero.

That wish was granted, with Friday’s scheduled fight taking place less than 30 minutes from Butler’s hometown. The 33-year-old contender made his 2010 pro debut in Liverpool, with the city hosting nearly half of his 35 pro bouts to date. Butler’s last appearance there came in a March 2019 stay busy win in his second fight following a twelve-round loss to then-unbeaten Emmanuel Rodriguez in their May 2018 vacant IBF bantamweight title fight.

Butler has fought twice since the pandemic, earning an eight-round win over Ryan Walker in October 2018 and a ten-round split decision over Willibaldo Garcia last June 25 in Bolton, England.

The April 22 date satisfied a deadline imposed by the WBO last December, stating that the fight must take place no later than April 30, 2022. The extensive amount of time between mandatory title defenses leaves zero tolerance in place for either fighter to drop out of the fight.  

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox