The South Dakota Supreme Court ruled Thursday that affidavits from an investigation into child pornography allegations against billionaire philanthropist T. Denny Sanford must be unsealed.

In 2019, South Dakota investigators searched his email account, as well as his cellular and internet service providers, for evidence of possession of child pornography, after his accounts were flagged by a technology firm.

Sanford, the state’s richest man, was not charged after the South Dakota attorney general’s office said its investigation into the allegations found no prosecutable offenses within the state’s jurisdiction.

Sanford had sought to bar affidavits used to issue search warrants in the case. But the Sioux Falls Argus Leader and ProPublica argued in court that the documents should be made public.

After the decision not to file charges, Judge James Power ordered in June 2022 that South Dakota law required the affidavits to be unsealed. They were kept sealed while Sanford’s attorneys appealed, sending the case to the state Supreme Court.