Russian authorities on Thursday froze a slew of bank accounts linked to jailed opposition politician Alexei Navalny as part of a money laundering investigation, Kira Yarmysh, his spokeswoman, and Russian investigators said.

Russia’s Investigative Committee announced during protests in Moscow last weekend that it had opened a criminal case into the laundering of 1 billion rubles ($15.3 million) by Navalny’s Anti-Corruption Foundation (FBK). Authorities raided the FBK’s office in Moscow as part of the investigation, the committee said Thursday.

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