A Russian court sentenced Alexei Navalny to nine years in a high-security prison Tuesday, imposing a new punishment on the imprisoned opposition leader at a time when the war in Ukraine has made him even more of a liability for Russian President Vladimir Putin.

Prosecutors had claimed that Navalny, a relentless critic and frequent target of Putin, and Navalny’s Anti-Corruption Foundation — which the Russian authorities banned as extremist last year — had embezzled donations from supporters.

"Navalny committed fraud, that is, the theft of other people’s property through deceit and breach of trust,” the judge, Margarita Kotova, said in reading her verdict, according to the news agency Interfax.