Amateur fighters run the risk of serious injury if they come up against professionals at at Tokyo 2020, the World Boxing Council (WBC) have warned the International Olympic Committee (IOC).
Any professionals who compete at next year's Olympic Games the Japanese capital will be banned from competing in fights organised by the WBC for two years, they have confirmed.
Unified world heavyweight boxing champion Andy Ruiz Jr had originally thought about representing Mexico at Tokyo 2020 before changing his mind.
The WBC have campaigned against plans for professionals to compete in the Olympic Games since the initiative was launched by the International Boxing Association (AIBA) before Rio 2016 because they claim it is dangerous for them to fight amateur boxers.
As well as deciding at its 57th Annual Convention in Cancun to issue the threat of suspensions for boxers taking part at Tokyo 2020, the WBC also announced they had written to the IOC about the matter.
Delegates were told the letter was intended to highlight and underline "the controversial issues of seasoned powerful professionals being allowed to fight against and likely dominate callow amateur youth, with all the risks of injury and the willful crushing of young dreams".
WBC-affiliated boxing federations in the United States, Canada, Japan, Spain, Portugal and Switzerland have already underlined their opposition to professionals fighting in the Olympic Games.
"A four rounds fighter has very different characteristics from a 12 round champion," WBC President Mauricio Sulaiman said.
"There is a very different attitude between amateurs and pros.
"We at the WBC have no other agenda apart from the protection of the boxers."
The consequences for those professional boxers who decide to compete at Tokyo 2020 will be severe, Sulaiman warned.
"Well they’re simply expelled from WBC activity for two years," he said.
Three professional boxers qualified to fight at Rio 2016, all of whom are more than 30 years old, and none of them were able to win against largely younger competition more than once.
Among those defeated was Cameroon's Hassan N'Dam, the former World Boxing Organization and World Boxing Association middleweight champion, who lost to Brazil’s Michel Borges in the 81-kilograms category.
N'Dam, who had fought at Athens 2004 as an amateur, blamed his defeat on poor judging.
Earlier this year, AIBA was stripped of its right to host the boxing tournament at Tokyo 2020 because of poor governance and alleged financial mis-management.
Boxing at Tokyo 2020 will instead be organised by an Ad-hoc IOC Task Force led by Morinari Watanabe, President of the International Gymnastics Federation.