On Friday, Alexei Navalny, the most significant domestic adversary of Russian President Vladimir Putin, lost consciousness and passed away after taking a walk at the "Polar Wolf" Arctic penal colony, where he was serving a three-decade sentence, authorities announced.

The passing of Navalny, a 47-year-old ex-lawyer, deprives the diverse Russian opposition of its foremost figure, just as Putin gears up for an election that will potentially extend the former KGB operative's rule until at least 2030.

President Joe Biden expressed outrage and joined fellow Western leaders in condemning Russia for Navalny's demise, attributing it to "actions carried out by Putin and his associates."

More than ten years ago, Navalny gained prominence by exposing and publicly denouncing what he claimed was extensive corruption and extravagance among the "crooks and thieves" governing Putin's Russia.

There are no opposition leaders in Russia who match Navalny's prominence.

For certain young urban Russians, Navalny represented a beacon of hope for an alternative future to Putin, who has held the reins of power in Russia longer than any leader since Josef Stalin.

The Federal Penitentiary Service of the Yamalo-Nenets Autonomous District stated that Navalny became ill following a walk at the IK-3 penal colony in Kharp, approximately 1,900 km (1,200 miles) northeast of Moscow.

He lost consciousness almost immediately and passed away shortly afterward, the statement mentioned, noting that attempts at resuscitation were unsuccessful.

According to Navalny's spokeswoman, Kira Yarmysh, the likelihood of him being alive was "almost nonexistent."

Yulia Navalny, Navalny's wife, expressed uncertainty at the Munich Security Conference, stating she couldn't confirm her husband's death due to the constant dishonesty of "Putin and his government."