An undisclosed number of referees and judges were sent home from the Rio Olympics by the International Boxing Association because of controversial decisions, one of which drew the anger of Ireland’s Michael Conlan and the attention of Floyd Mayweather Jr.

“Less than a handful of the decisions were not at the level expected,” the organization (AIBA), which oversees amateur boxing, said in a statement.

Two results were especially controversial. Judges awarded a victory to Russia’s Vladimir Nikitin, although Conlan appeared to have beaten him in a 56-kilogram division quarterfinal. Gary Russell of the U.S. team and the Washington D.C., area, had “clearly been robbed,” according to boxing champion Mayweather, in his split-decision loss to Uzbekistan’s Fazliddin Gaibnazarov.

On Monday, Evgeny Tishchenko of Russia won the heavyweight gold medal by unanimous decision as all judges scored the fight with Kazakhstan’s Vassiliy Levit 29-28.

“AIBA will not shy away from its responsibilities and is fully committed to a zero tolerance policy towards fair play in boxing, always acting in the boxers’ utmost interest,” the AIBA’s statement said.

All the decisions remain final and the organization did not identify the individuals or the fights they worked.

Conlan was furious Tuesday, leveling the boxing organization in a profanity-laced tirade on Irish TV and flipping off the judges with both hands.

“AIBA cheats,” he said (via Yahoo). “They’re [expletive] cheats. I’ll never box [under] AIBA again. They’re cheating bastards. They’re paying everybody. I don’t give a [expletive] that I’m cursing on TV.”

AIBA responded by demanding proof of cheating.

“With regard to corruption, we would like to strongly restate that unless tangible proof is put forward, not rumors,” the statement said. “We will continue to use any means, including legal or disciplinary actions to protect our sport.

“The organization will not be deterred by subjective judgments made by discontented parties. We welcome all parties to come forward and provide evidence in order to take appropriate and immediate action.”