Dr. Richard Keller, a former medical director at Phillips Academy in Andover who is ­accused of receiving child pornography, was a volunteer with Jewish Big Brothers Big Sisters of Greater Boston , a leader of that program said Thursday.

Chief executive Harvey Lowell said Keller, 56, was a “big brother” from 1986 to 2003. During that time, he was paired with five children as his “little brothers,” a spokeswoman for the group said.

“We have been in touch with the former little brothers and there have been no allegations of any wrongdoing,” Lowell said.

Keller was arrested Sept. 13 at his Andover home, where federal prosecutors said they found hundreds of sexually explicit photographs of minors and dozens of DVDs. He drew investigators’ attention after his name appeared in the customer database of a foreign company that produced child pornography, according to an affidavit filed in federal court.

Keller’s attorney, Max Stern, has not returned calls for comment. Keller has been placed on leave from his positions as a Harvard Medical School instructor and a part-time pediatric endocrinologist with Boston Children’s Hospital. He also worked at a summer camp for boys in the Berkshires and at Camp Joslin in Charlton for boys with diabetes.

Keller has agreed with the state Board of Registration in Medicine to stop practicing in Massachusetts, and he waived his right to request bail . The New Hampshire medical board also has suspended his license.