An investigation into South Dakota’s richest man for possible possession of child pornography remains ongoing, according to new documents filed by authorities in court. The billionaire T. Denny Sanford has been under investigation since 2019, when the state first obtained search warrants into his electronic activity; those warrants were unsealed in the fall, though affidavits further detailing the inquiry are still under seal. Sanford’s lawyer, former South Dakota attorney general Marty Jackley, has previously pushed back on the allegations, and in a court filing of his own he claimed that the billionaire’s email account had been hacked during the time period of the alleged misconduct, including within 10 days of when the first search warrant was issued. Court documents also revealed that authorities began looking into Sanford after receiving a tip from a nonprofit called the National Center for Missing & Exploited Children.