A 67-year-old Westport man and teacher at a Norwalk high school has been charged with sexually assaulting a child for whom he was babysitting, police said.

Victor Corso of Hillandale Road was taken into custody Monday, and charged with risk of injury to a child and fourth-degree sexual assault.

The incident took place when Corso was babysitting for the child at his home, police said. A sexual-abuse complaint about Corso was forwarded to police Dec. 26 from the state Department of Children and Families, and based on the police investigation, criminal charges were filed against Corso.

He is a teacher at Brien McMahon High School in Norwalk, police confirmed Wednesday.

Corso was held on $150,000 bond and scheduled to be arraigned on the charges Wednesday in Norwalk Superior Court.