In Putin’s Russia, the Arrests Are Spreading Quickly and Widely
Now, he said in a phone interview, the family has to return Mr. Kolker’s body from Moscow at their own cost.

It was unclear why the F.S.B. targeted Dmitri Kolker, 54, a specialist in quantum optics. State media reported that he had been jailed on suspicion of passing secrets abroad. But critics of the Kremlin say it is part of a widening campaign by the F.S.B. to crack down on freedom of thought in the academic world. Another Novosibirsk physicist who was also arrested on suspicion of treason last week, Anatoly Maslov, remains in custody.

The arrests came at the same time as the arrest on fraud charges of Mr. Mau, a leading Russian economist who is the head of a sprawling state university, the Russian Presidential Academy of National Economy and Public Administration.

Mr. Mau, 62, was in no way a public critic of the Kremlin. He had joined more than 300 senior academic officials in signing a March open letter calling Russia’s invasion of Ukraine a “necessary decision,” and he was re-elected to the board of Gazprom, the Russian energy giant, just last week. But he also had a reputation as what scholars of Russian politics call a “systemic liberal,” someone who was working within Mr. Putin’s system to try to nudge it in a more open and pro-Western direction.

His Kremlin ties were not enough, it turned out, to save Mr. Mau from a fraud case that has already ensnared the rector of another leading university and that critics said appeared designed to snuff out remaining pockets of dissent in Russian academia.

“A big enemy of the government and the stability of the government are people who carry knowledge,” said Mr. Gozman, who worked with Mr. Mau as a government adviser in the 1990s. “Truth is an enemy here.”