Simon Cho addresses a news conference at which he publicly confessed to damaging the skate blade of a Canadian rival. (Tom Smart/Associated Press)

Calling Simon Cho’s sabotage of a Canadian rival’s skates an “egregious breach of our code of conduct,” U.S. Speedskating officials announced Friday that they were launching an immediate disciplinary proceeding to determine what punishment to mete out against the 2010 Olympic short-track bronze medalist.

In addition, officials placed short-track racing’s interim national coach, Jun Yeo, on administrative leave for having known about Cho’s transgression when it occurred at the World Championships in Warsaw and failing to report it.

Jae Su Chun, a South Korean native who was named the U.S. national coach in 2007, was placed on administrative leave Sept. 16 amid wide-ranging claims of physical and mental abuse leveled by 12 of the country’s elite short-track skaters — roughly half the national team.

Friday’s action effectively leaves U.S. short-track speedskating without a coach just weeks before the fall World Cup season begins and 16 months before the 2014 Winter Olympics in Sochi get under way.

Cho, 20, who trained at the Potomac Speedskating Club in Arlington, told representatives of White & Case, a law firm retained by U.S. Speedskating to investigate the claims of abuse, that he damaged the skate of Canada’s Olivier Jean on Chun’s orders. A public confession followed Friday.

The tampering episode came to light as part of a legal effort by current and former skaters to get Chun and his assistants removed from their posts. In a complaint to U.S. Speedskating, which was followed by a grievance filed with the U.S. Olympic Committee and a demand for arbitration, the skaters cited 22 instances of physical and emotional abuse by Chun, including throwing chairs and water bottles at athletes, over-training athletes to the point of injury and calling female skaters “fat” and “worthless.”

But the law firm investigating the claims did not find evidence that constituted physical or emotional abuse or “a pattern of abuse.” An executive summary of the report was provided to U.S. Speedskating officials Friday in response to Cho’s public confession about sabotaging the Canadian’s skates.

Asked whether the report exonerated Chun, Greg Little of White & Case said it neither exonerated nor endorsed Chun’s methods.

With Cho’s confession public, U.S. Speedskating officials, joined by a representative from White & Case, held a news conference to discuss the executive summary of the investigation into the allegations against Chun.

“Coach Jae Sue generated a very strong emotional reaction,” Little said. “[There are] a large number of skaters who still strongly support Coach Jae Su and his methods, [and] a large number who are equally disappointed about his methods and feel they do not benefit them. There are two polarized groups with respect to Coach Jae Su Chun.”

Chun’s return to his post is far from certain. The investigation revealed that he knew of the skate-tampering incident the moment it happened and, like Yeo, failed to report it, which constitutes grounds for potential disciplinary action.

An arbitration hearing is scheduled for Nov. 1.