BOSTON (AP) — A federal grand jury has indicted the former medical director of an exclusive Massachusetts prep school on multiple child pornography charges.

Physician Richard Keller of Andover faces two counts of receiving child pornography and one count of possessing child pornography following Tuesday’s indictment.

Authorities arrested the 56-year-old in September on a charge of receiving child pornography, and alleged he’d had child porn delivered to him at Phillips Academy campus before his 2011 resignation.

Authorities said they seized hundreds of photos and several dozen DVDs of child porn from his home.

The indictment charges Keller possessed depictions of minors in sexually explicit conduct, including boys from about 7 to 16 years old.

Keller, who worked at Boston Children’s Hospital and taught at Harvard Medical School, has a Dec. 18 arraignment.

His lawyer couldn’t be immediately reached for comment Wednesday.

Copyright 2012 The Associated Press.