SPRINGFIELD TOWNSHIP, Ohio -- Deputies in Clark County said a 10-year-old boy was arrested Wednesday on a rape charge.

Investigators said the boy is accused of having sex with his 7-year-old stepsister. The boy is being held in Juvenile Detention.

Det. Jim Conley said, “This is very unusual. To my knowledge, this is the only case of this type that we have had in the last year or so.”

Deputies said the alleged rape happened sometime between Dec. 21 and Dec. 25 in the home where the two children lived with the girl’s mother.

The case remains under investigation.