US boxing coach Billy Walsh said on Wednesday the standard of judging at these Olympics is the worst he's seen since the notorious Roy Jones Jr. scandal in 1988.

Amateur boxing's world governing body, AIBA, said it had dropped an undisclosed number of officials after at least two highly controversial judging decisions in as many days put Rio's ring in the spotlight. Walsh watched US lightweight Mikaela Mayer lose on points to a Russian in front of a mostly anti-US crowd on Monday, a decision he branded "crazy."

A few hours later, a Russian heavyweight was judged to have won the gold medal showdown against a Kazakh when most in the crowd thought otherwise. And on Tuesday, an Irish world champion lost to a third Russian boxer.

Walsh said he was relieved reigning Olympic middleweight champion Claressa Shields escaped a similar fate against Russia's Iaroslava Iakushina.

"There have been a couple of favorites beaten here already, and you can never know with the way things have been going," Walsh said. "You can never be sure of a decision."

Asked where the standard of judging in Rio ranked compared to what he had seen at past Olympics, Walsh said: "To me it is back to where we were in 1988, when Roy Jones got robbed."

That final at the Seoul Games has gone down as the most notorious decision in Olympic boxing history. Judges awarded victory to home fighter Park Sihun despite him taking a beating from Jones - a future world champion in the pro ranks - who wept when the decision was announced.

The scoring system was later changed.

(China Daily 08/19/2016 page5)