PETROZAVODSK, Russia -- A court in Russia's northwestern region of Karelia has sentenced historian and human rights activist Yury Dmitriyev to 3 1/2 years in prison on sexual assault charges involving his adopted daughter, which he and his supporters vehemently deny.

About 100 people, including Dmitriyev's relatives and friends, human rights activists, opposition politicians, and others gathered in front of the Petrozavodsk City Court on July 22 when Dmitriyev's verdict and sentence were pronounced behind closed doors.

Dmitriyev's lawyer, Viktor Anufriyev, said that the court dropped other charges of making pornographic materials, sexual misconduct, and illegal weapon possession against his client.

The Petrozavodsk City Court's website said Judge Aleksandr Merkov found Dmitriyev guilty of "violent acts of a sexual nature committed against a person under 14 years of age."

According to Anufriyev, his client may be released as early as November if time served during investigations and the trial are taken into account.

It was not immediately clear whether Dmitriyev plans to appeal the verdict.

Prosecutors had asked the court to sentence Dmitriyev to 15 years in prison.

The high-profile case dates back to 2016, when Dmitriyev was arrested on child-pornography charges based on photographs of his daughter that authorities found on his computer.

He has proclaimed his innocence, contending that the images were not pornographic and were made at the request of social workers concerned about the child’s development.

A local court acquitted Dmitriyev in April 2018, but the Karelia Supreme Court subsequently upheld an appeal by prosecutors and ordered a new trial.

The historian was rearrested in June 2018 and charged with a more severe charge of "violent acts of a sexual nature committed against a person under 14 years of age" -- again referring to his daughter.

'Spurious' Charges

Supporters of the 64-year-old, who is also the head of the Karelia branch of the Moscow-based human rights group Memorial, have said the charges were brought against him because of his research into a side of history that complicates the Kremlin's glorification of the Soviet past.

Dmitriyev's decades-long efforts to expose the extent of Soviet dictator Josef Stalin's crimes have been viewed with hostility by the government of President Vladimir Putin.

Ahead of the verdict, Human Rights Watch (HRW) expressed concern about the case, casting doubt on its validity.

The "circumstances surrounding criminal charges" against Dmitriyev "strongly suggest that they are spurious and target him for his human rights work," HRW said in a statement.

In May, dozens of Russian scholars, historians, writers, poets, opposition politicians, artists, and actors signed an open letter asking the Karelia Supreme Court to release Dmitriyev, expressing concerns over the researcher's health as coronavirus infections have been found in the detention center where he is being held.

The European Union has called on the Russian authorities to release Dmitriyev and reconsider the charges against him.

With reporting by Kommersant and Novaya gazeta