NORWALK (CBS) — A 63-year-old La Palma man has been arrested on suspicion of sexually assaulting a young girl he tutored at the Kumon Learning Center in Norwalk.

Frank Chung, who owns the center and has been providing students with after-school tutoring for five years, has also worked at other centers across the state.

Deputies launched an investigation after the alleged 13-year-old victim was overheard telling her sibling about inappropriate sexual contact she had with Chung on several occasions.

Chung was arrested Thursday at his residence and is being held on $1 million bail.

Detectives with the Sheriff’s Department’s Special Victims Bureau believe there may be more victims.

Anyone with information about the case was asked to call (877)710-LASD(5273). Tips can also be submitted by texting the letters TIPLA plus your tip to CRIMES (274637), or using the website http://lacrimestoppers.org.