“Someone broke a car window and sprayed tear gas in his eyes, after which the attacker started hitting Leonid with a hammer,” Yarmysh wrote late Tuesday on X. “Leonid is now at home, police and ambulance are on their way to him.”

Navalny’s Anti-Corruption Foundation, of which Volkov once served as chairman, posted photos on X of Volkov with a bloodied leg and swollen face. The organization also posted a photo of a car’s smashed window.

Navalny founded the Anti-Corruption Foundation in 2011 to investigate alleged corruption by high-ranking Russian officials, increasingly including those within the Kremlin elite. The foundation was outlawed by Russia.

Maria Pevchikh, director of the foundation, also reported the attack on Volkov, writing on X that he was “beaten up with a hammer.”