A longtime wrestling coach and coordinator of the state high school wrestling championships is awaiting trial in state court for third-degree sexual assault for allegedly inappropriately touching a 15-year-old girl last month during a wrestling tournament at Farrington High School.

The girl is a wrestler who competed in the tournament.

According to a June 19 grand jury indictment, Keith T. Matsumoto caused the girl to have sexual contact with him by "placing his hand on her buttock."

Matsumoto, 54, pleaded not guilty at his arraignment July 2 and is scheduled to go to trial in September.

His lawyer, Tommy Waters, said he is going to conduct a thorough investigation into what happened at the tournament.

"We look forward to resolving this matter in an amicable way. And if it is necessary to go trial, I will vigorously defend my client," Waters said.

The alleged incident happened June 9, the second day of a two-day tournament, attended by hundreds of people, billed as the 2012 Greco Roman and Freestyle Hawaii State Championships presented by Hawaii USA Wrestling. The tournament was not a Hawaii High School Athletic Association event.

Police arrested Matsu­moto at Farrington while tournament matches were still going on. They released him June 10 after Matsumoto posted $11,000 bail.

The Hawaii USA Wrestling officials listed as the tournament administrator and tournament facilitator would not comment.

Matsumoto is not the girl’s wrestling coach and was not listed as a USA Wrestling or a tournament official.

Waters said Matsumoto was at the tournament helping out. He said Matsu­moto is also a coach for Team Hawaii, club wrestlers who represent the state in national tournaments.

USA Wrestling publishes a strict policy against abuse and harassment by its members, participants, coaches, officials and volunteers.

At the 2012 HHSAA Wrestling State Championships at the Neal Blaisdell Arena in March, Matsumoto served as the tournament coordinator and a site manager and also served on the protest committee. He was also listed as an official for the weigh-in, rules, scoring and officiating.

Matsumoto is also the Hawaii editor of Wrestling USA Magazine.