The son of a New Hampshire police chief has been indicted on federal child pornography charges.

Court papers filed in the United States District Court of New Hampshire in Concord charge now-21-year-old Tyler LaVoie, son of Hudson Police Chief Jason LaVoie, with two counts of possessing and receiving child pornography.

An investigation of nearly four years by FBI agents found that in 2014, the file storage website DropBox reported 90 images and videos of child porn to the National Center for Missing and Exploited Children.

The images were traced to an account under the name "Ty Jackson," belonging to Tyler LaVoie.

Two years later, in 2016, DropBox reported a second set of images that included child pornographers to the NCMEC linked to the same user name.

Court papers say a year later in 2017, the FBI seized an iPhone with pictures and videos from a Londonderry home.

NBC10 Boston knocked on the door of the Londonderry home, but a family relative offered no comment.

Court papers say that the younger LaVoie said his relationship with child porn started as a "cyber vigilante" who was responsible for the removal of child pornography from DropBox.

Investigators say he later admitted to enjoying it and that it spiraled out of control.

NBC10 Boston reached out to Hudson's police chief, but he remained unavailable to speak with us. We also reached out to Tyler LaVoie's attorney, Charles Keefe. His office said he was in court and unavailable to speak.