Nikita Belykh, the liberal former governor of Russia's Kirov region, pleaded not guilty as his trial on a bribe-taking charge got under way in Moscow on September 5.
Belykh called the charges against him "absurd" and told the court he is "absolutely not guilty."
"Everything that is happening here is a police provocation," Belykh said.
Once a leader of a liberal opposition party, the Union of Right Forces, he was one of the few provincial governors not to be closely allied with President Vladimir Putin.
Russian investigators detained Belykh in June 2016, saying they had caught him accepting a bribe of 400,000 euros ($475,000) at a Moscow restaurant.
Belykh, who has described his arrest as unlawful, was dismissed from the post of governor by Putin in July 2016.