A postmaster for the U.S. Postal Service was arrested  Thursday following a months-long investigation into allegations he engaged in sexual communications with a minor.

Chad Miller, 45, is being held on suspicion of two counts of internet sexual exploitation of a child and sexual exploitation of a child, the Jefferson County Sheriff’s Office announced Friday.

Investigators began looking into Miller’s conduct last August when he allegedly began communicating with a member of the Cheezo Unit — or Special Investigations Unit — within the sheriff’s office.

The sheriff’s office said Miller believed the investigator he was communicating with was 13 years old. Despite her age, Miller told the investigator who was posing as the minor, that he wanted to have sex, according to a release from the sheriff’s office.

Miller eventually stopped talking to the minor but resumed online communication between March 9 and March 30. He told the investigator he was a postmaster “and continually engaged in detailed sexual communications,” according to the release.

Officials contacted Miller on Thursday at the post office in Elizabeth and took him into custody. He is scheduled to appear in court on April 7, according to online court records