A pediatric cardiac anesthesiologist at Boston’s Children’s Hospital has been arrested on Johnathan Walkercharges of possessing and distributing child sexual abuse material, federal prosecutors said.

The 35-year-old physician made an initial appearance in court Friday and was detained pending a hearing Tuesday, the U.S. attorney’s office said in a news release.

The charges allege that he knowingly distributed and possessed videos and images between July 1 and July 18 following a search of his home and phone.

A phone number for the anesthesiologist could not be found. An email seeking comment from his attorney was left Saturday.

Boston Children’s Hospital said in statement that it had terminated the man’s employment following his arrest.

The anesthesiologist had started a fellowship at the hospital on July 1 and had previously worked at Johns Hopkins University in Baltimore, according to a police affidavit filed in court.

A federal investigation began in Baltimore in May into a member of a group on an encrypted messaging app that required users to upload nude imagery of children. The anesthesiologist was identified as that user, the affidavit said.