Russia’s Federal Antimonopoly Service announced on Monday that it’s uncovered a price-fixing cartel in the Defense Ministry’s procurement contracts, and the companies involved are the same ones opposition leader Alexei Navalny says belong to Yevgeny Prigozhin, the billionaire known as “Vladimir Putin’s favorite chef.” Antitrust officials say the cartel coordinated procurement bids to inflate prices on contracts.

The agency’s announcement doesn’t mention Prigozhin, however, and it limits the cartel’s actions to deals worth 2 billion rubles, not the 23 billion rubles in contracts Navalny’s group says went to Prigozhin’s companies.

The St. Petersburg news site Fontanka was the first to report Prigozhin’s possible ties to defense contracts worth billions. In January 2016, the website published a story about five unknown companies founded by retired police officers and supposedly controlled by Prigozhin. The year before, these businesses won no-bid defense deals worth almost 30 billion rubles ($530.2 million).