Jailed Russian opposition leader Alexei Navalny said on Wednesday that investigators had opened what he called an "absurd" terrorism case against him that could see him sentenced to an additional 30 years in jail.
Navalny, a former lawyer who rose to prominence by lampooning President Vladimir Putin's elite and alleging vast corruption, is serving combined sentences of 11-1/2 years for fraud and contempt of court on charges that he says were trumped up to silence him.
The 46-year-old opposition leader appeared in a Moscow court via video link on Wednesday, dressed in a black Russian prison jacket and looking gaunt, as part of a case into extremism, Reuters reporters at the court said.
It was the first time he was seen in public since his supporters said earlier this month that he was suffering stomach pain in jail that could be some sort of slow acting poison. He smiled and joked with reporters until his video link was muted.
"They have made absurd accusations, according to which I face 30 years in prison," he said in a statement published by his supporters.
It was not immediately clear what the terrorism case could relate to but Russia's Federal Security Service, the main successor to the Soviet-era KGB, said that Ukraine and Russian opposition figures from a fund set up by Navalny were behind the killing of a prominent war blogger in a St Petersburg cafe.
Navalny said it was absurd to argue he had committed terrorism while in prison. He said the case would be tried by a military court.
Russia ups fight against opposition leaders
Less than a year ahead of a 2024 presidential election which Putin is expected to run in, Russian courts and security services have been upping their fight against perceived enemies, spies and traitors.
Navalny earned admiration from Russia's disparate opposition for voluntarily returning to Russia in 2021 from Germany, where he had been treated for what Western laboratory tests showed was an attempt to poison him with a nerve agent in Siberia.
Navalny says he was poisoned in Siberia in August 2020. The Kremlin denied trying to kill him and said there was no evidence he was poisoned with a nerve agent.
His supporters cast him as a Russian version of South Africa's Nelson Mandela who will one day walk free from jail to lead his country.
But Russian authorities view him and his supporters as extremists with links to the United States' CIA intelligence agency who are seeking to destabilize Russia. They have outlawed his movement, forcing many of his followers to flee abroad.
His campaigning organizations have been banned in Russia as "extremist."
This month Russian investigators formally linked Navalny supporters to the murder of Vladlen Tatarsky, a popular military blogger and supporter of Russia's military campaign in Ukraine, who was killed by a bomb in St Petersburg. Navalny allies have denied any connection to the killing.
Separately on Wednesday, Russian investigators said that 11 people had been put on an "international wanted list" in a case linked to Navalny, state-owned news agency TASS reported.