A high-profile corruption case shook Russia’s establishment and appeared to shed light on a power struggle within President Vladi­mir Putin’s inner circle on Tuesday, after authorities detained the country’s economic development minister on suspicion that he demanded and accepted a $2 million bribe over a controversial privatization deal.

Alexei Ulyukayev became the highest-ranking official to be charged with corruption during Putin’s tenure as Russia’s leader, and the first national minister to be arrested while in office since Joseph Stalin’s dreaded security chief Lavrenti Beria was detained in the Kremlin in 1953 after the Soviet dictator’s death.

Some Putin critics saw Ulyukayev’s arrest as a tactic by the Russian leader to keep his senior lieutenants in check.

“The arrest of such a loyal and important official as Ulyukayev is a powerful act of intimidation, first of all, for the benefit of officials,” Grigory Yavlinsky, leader of the liberal Yabloko party, said in a Facebook post. “Everyone should know: Anything can happen to you at any moment; that’s the main message.”