PORTLAND, Ore. (KOIN) -- An Oregon high school principal was arrested Tuesday on child pornography charges, officials said.

In August, the Cowlitz County Sheriff's Office said it received multiple referrals from the National Center for Missing and Exploited Children about incidents involving child sexual assault material.

Officials said the information came from social media sites, which had reported multiple images with 'hash' matches to known child sexual assault material received by accounts belonging to a Longview, Washington resident.

According to the Sheriff's Office, hash matching is a process where a "hash" is generated for a digital file, and then that hash can be compared against a database to find identical content that was labeled as child sexual assault material.

Detective

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