HILO, Hawai'i — The parents of a 4-year-old girl say she was sexually assaulted by a man with mental disabilities two years ago at a busy Hilo gymnasium and are suing the man and his caregivers, alleging the man was improperly supervised.

The suit filed in Hilo Circuit Court Wednesday says the girl was attending a youth volleyball tournament at the Hilo Armory Gym on Nov. 22, 2003, with her mother and two sisters when the assault took place. The child's mother was a coach and referee in the tournament, according to the suit.

The Advertiser is not releasing the name of the 21-year-old man because he has not been charged in connection with the allegations. Big Island Deputy Prosecutor Darren Ching said the county is still reviewing the case to determine whether criminal charges are appropriate.

The suit against the man and the social service agency Child and Family Service was filed on behalf of Hilo lawyer Andrew P. Wilson as the child's legal representative, and by the child's mother and father.

It says the man was attending the athletic tournament with his personal assistant, who was allegedly an employee of Child and Family Service. During the tournament, the man allegedly sexually assaulted the child in a bathroom of the gym, according to the suit.

According to the suit, the man suffers from physical and mental disabilities, and the personal assistant who was with him "knew or should have known" the man's condition would lead to "inappropriate and/or illegal sexual misconduct" if he were not supervised.

The suit also faults CFS for allegedly failing to properly train and supervise the personal assistant, and seeks punitive and other damages.

Elisa Yadao, spokeswoman for Child and Family Service, said the agency has not been served with the suit, and declined comment.

According to a guardianship petition filed by the man's mother in Hilo Circuit Court in 2002, the man suffers from cerebral palsy and mental retardation "with occasional aggressive behavior."

He was on probation as a juvenile until 2002 in connection with another offense, and before the alleged Hilo Armory Gym incident had been undergoing treatment to address problems that included "anger management skills and sexual offensive behavior," according to court records.

Juvenile criminal cases are not public records, and no other information was available about the man's juvenile case.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.