His lawyer said Russia on Friday ordered the preventive arrest of opposition leader Vladimir Kara-Murza, one of the Kremlin’s main critics, as part of an investigation into “false information” about the military’s activities in Ukraine.

Lawyer Vadim Prokhorov said in a statement posted on Facebook that the Moscow court “detained Vladimir Kara-Murza until June 12”.

The court confirmed this information in a statement released by Russian news agencies.

Prokhorov announced in the morning that Kara-Murza was being questioned by the Russian Investigative Committee as part of the investigation into the spread of “false information” about the army.

Disclosure of “false information about the use of the Russian armed forces” is punishable by up to 15 years in prison, according to a new article of the penal code approved in early March.

The country’s legal arsenal has been strengthened to check what has been published about the military operation in Ukraine. Using the words “war” or “invasion” to describe interference is sufficient to prosecute.

In recent weeks, 40-year-old Kara-Murza has repeatedly criticized the interference in Ukraine, including on social media.

On April 12, he was sentenced to 15 days in prison for humiliation.

Kara-Murza is a former journalist close to dissident Boris Nemtsov, who was killed near the Kremlin in 2015, and to Mikhail Khodorkovsky, a former oligarch who was critical of President Vladimir Putin.

The opposition, who continues to live in Russia, said that he was poisoned twice in 2015 and 2017 due to his political views.

Kara-Murza was declared a “foreign agent” on Friday, along with several journalists, including Alexei Venicetov, the director of the Moscow-distributed radio station Eco.

Russia’s Ministry of Justice said in a statement it added eight people to its list of “foreign agents”, including Leonid Volkov, right-hand man of Russian opposition leader Alexei Navalny, and senior journalist Alexander Nevzorov.