Alexei Navalny, the prominent Russian opposition leader, has died after collapsing and losing consciousness at the penal colony where he was serving a jail term, the Russian prison service confirmed on Friday.

Navalny, 47, who became widely known for his vocal criticism of President Vladimir Putin and allegations of widespread corruption among the Russian elite, was serving his sentence at the IK-3 penal colony in Kharp, located approximately 1,900 kilometers northeast of Moscow.

The Federal Penitentiary Service of the Yamalo-Nenets Autonomous District released a statement saying Navalny “felt unwell” after a walk at the facility before losing consciousness almost immediately.

Despite immediate medical attention and resuscitation efforts, Navalny could not be revived.

The world has lost a fighter whose courage will echo through generations.

Horrified by the death of Sakharov Prize laureate Alexei Navalny.

Russia took his freedom & his life, but not his dignity.

His struggle for democracy lives on.

Our thoughts are with his wife & children. pic.twitter.com/JMSAkLpb0T

— Roberta Metsola (@EP_President) February 16, 2024

Cause of death

“The medical staff of the institution arrived immediately, and an ambulance team was called,” the statement read. “All necessary resuscitation measures were carried out, which did not yield positive results. Doctors of the ambulance stated the death of the convict.”

The exact cause of Navalny’s death is currently under investigation.

Let’s make no mistake, Putin assassinated Navalny. He did so because Navalny was brave enough to stand up to Putin. He did so because Navalny offered the Russian people and alternative to kleptocracy and repression. This is a tragic day for Navalny’s family but also for Russia https://t.co/TwgOQIb70D

— Bill Browder (@Billbrowder) February 16, 2024

Kremlin spokesman Dmitry Peskov confirmed that President Putin had been informed of Navalny’s death.

Navalny gained widespread international attention in 2020 when he was poisoned with a nerve agent, according to Western laboratory tests, while in Siberia.

He was later treated in Germany. Despite the attempt on his life, Navalny returned voluntarily to Russia in 2021, where he was subsequently arrested and imprisoned.

Yesterday Navalny looked to be fine during a court hearing where he spoke via video link from his penal colony pic.twitter.com/e8HoAnWsQB

— Francis Scarr (@francis_scarr) February 16, 2024

The Kremlin has consistently denied any involvement in Navalny’s poisoning and has refuted claims of attempting to assassinate him.

Navalny’s death marks a significant loss for Russia’s opposition movement, with Navalny having garnered admiration from various quarters for his courage and outspoken criticism of the government.