Russian opposition leader Alexei Navalny, 47, reportedly died in prison on Friday in the penal colony where he was imprisoned north of the Arctic Circle in Kharp, called the "Polar Wolf". He collapsed and lost consciousness, per prison officials.

Navalny was the main the leading oppositiong to Russian President Vladimir Putin. He accused Putin of corruption and took aim at the nation's wealthy elites, as well, saying that they were greedy and lived in oppulence while the people suffered. 

US Ambassador to the Organization for Security and Cooperation in Europe Michael Carpenter said that Navalny was recently "thrown into a punitive isolation cell for an unimaginable 27th time." 

"Navalny faces a 15-day stint in solitary confinement, adding to the 293 days he's already endured. We condemn this ongoing assault on Navalny's rights and we call for his immediate release. #FreeNavalny," Carpenter said.