The Czech Boxing Association (CBA), Boxing Canada and the Swedish Boxing Association have said they will boycott the Women's and Men's World Championships this year due to the planned participation of Russia and Belarus under their national flags while Great Britain will be absent from the women's event.
The four countries join the United States and Ireland in planning to be absent from the International Boxing Association (IBA) events.
"We have given the same opinion as the Czech Boxing Association before," CBA President Marek Šimák told Radiožurnál Sport.
"The association is led by a Russian who is in a very close relationship with [Russian President Vladimir] Putin, and everything is paid for by Gazprom.
Boxing Canada said in a statement its boycott was due to the planned participation of Russian and Belarusian athletes, as well as a protest at the sport's governance.
"Given the continued corruption within the International Boxing Association, we have significant concerns surrounding the risk our sport faces and its future within the Olympic line-up," Boxing Canada President Ryan O'Shea said.
Swedish Boxing Association chairman Per-Axel Sjöholm said the IBA's decision to allow Russian and Belarusian athletes to feature was the main factor in their decision to join the boycott.
"We do not accept IBA's handling," said Sjöholm, as reported by Teller Report.
"Another reason is that the Olympics are much more important to us than the World Championships organised by IBA.
"So it was an easy decision for us in Sweden."
The IBA, formerly AIBA, has been suspended by the International Olympic Committee (IOC) since 2019.
Relations have continued to sour as boxing has been left off the initial Los Angeles 2028 programme and could still be dropped from Paris 2024.
Governance concerns, financial irregularities and a lack of transparency are key to the IOC's decision.
Šimák claims that more National Federations are considering the boycott and that there are discussions over the potential formation of a new organisation to replace the IBA.
"We are talking about it, and now the Germans have stepped in, and when they decide to do something like this, they usually have it ready," he said.
GB Boxing states that the decision to boycott the Women's World Boxing Championships was taken because of "ongoing concerns about the future of boxing’s place on the Olympic programme and the recent move by IBA to allow boxers from Russia and Belarus to compete under their national flags."
The governing body is considering whether to miss the men's event in May, with its Board to make a decision closer to the Championships.
Kremlev responded to the US and Irish boycotts claiming that officials who voted for it are "worse than hyenas and jackals".
USA Boxing also argued that the IBA had failed to "address the drastic change of culture requested by the IOC" and cited Kremlev's comments that "not a single boxer, coach or National Federation will be participating in the Olympic Games without IBA".
USA Boxing executive director Mike McAtee hit back at the IBA's statement, describing it as a "brazen public attack".
The Women's Boxing World Championships are scheduled for March 15 to 26 in New Delhi, followed by the Men's World Championships in Tashkent from May 1 to 14.