Dmitriev, 64, was found guilty in July of sexually abusing his adopted daughter and sentenced to 3-1/2 years in prison by the Petrozavodsk city court in Russia’s northwestern Karelia region. He had denied the charges, which his lawyer and supporters say were fabricated because of his work with rights group Memorial. They say his real crime was dedicating himself to documenting Stalin’s 1937-38 Great Terror by unearthing mass graves and chronicling state repression. Nearly 700,000 people were executed during that period, according to conservative official estimates. The July sentence would have seen Dmitriev freed in November due to time served, but Karelia’s Supreme Court said on its website on Tuesday that he would now be held for 13 years in a high-security penal colony. ADVERTISEMENT Artem Cherkasov, one of Dmitriev’s lawyers, said his client would appeal the decision, the Interfax news agency reported. The U.S. embassy in Moscow condemned the ruling. “The Karelian Supreme Court’s decision to prolong historian Yuri Dmitriyev’s already unjust sentence by an outrageous 10 additional years is another step backwards for human rights and historical truths in Russia,” spokeswoman Rebecca Ross said on Twitter. ADVERTISEMENT Dmitriev was cleared of initial child pornography charges involving his adopted daughter at a trial in 2018, but that ruling was later annulled and he was arrested on a new charge shortly afterwards. Fellow historians, rights activists and some leading cultural figures say Dmitriev was framed because his focus on Stalin’s crimes has become politically untenable in a modern Russia where the dominant state narrative is of a great nation rising from its knees. The Kremlin has said it is not involved in his case. Asked whether it was politically-motivated, state prosecutors have said the case is based on real evidence.