A world champion hacky sack player is accused of sexually assaulting a girl he knows in Ann Arbor about seven years ago, authorities said.

Greg M. Nelson, 42, of Ann Arbor, was arraigned Tuesday morning in 15th District Court on four counts of second-degree criminal sexual conduct, Ann Arbor police Det. Bill Stanford said.

Nelson, who turned himself in on a warrant early Tuesday, was released on a personal recognizance bond, court records show. He could not be reached for comment Thursday.

The victim, who is now 17, reported the assaults in March, Stanford said.

Nelson is a 12-time World Doubles Champion in hacky sack and a professional Frisbee player who works as an independent contractor for Flying Aces in Sharon Township. He performs in hacky sack and Frisbee shows for the company, including at school assemblies and half-time shows for college and professional basketball games.

Nelson has worked for the company for 23 years and will continue to perform because he hasn't been convicted of anything, said company owner Brian Hayes. Nelson also works as a handyman and is a former volunteer firefighter, Hayes said.

"He's like the most loyal, honest person I've ever met," Hayes said. "Everybody loves the guy. He never says anything bad about anybody.

"I just don't think there's any possible way in the world he's capable of doing something like that."

Lee Higgins covers crime and courts for AnnArbor.com. He can be reached by phone at (734) 623-2527 and email at leehiggins@annarbor.com.