The Russian prison service has said Alexi Navalny “fainted and died quickly”, the death of the political prisoner, opposition leader, and critic of the Russian President already being called a “political assassination”.

Anti-corruption campaigner and opposition party leader Alexi Navalny, who had previously survived a poisoning attempt by the infamous Russian nerve agent Novichok in 2020 and who has spent years in prison, has died, Russia says. A press release from a Russian state media outlet states President Putin has been informed of the death, which is said to have happened today.

At the time of his death, Navalny was serving a 19-year prison sentence at an Arctic penal colony. Navalny had been branded a “terrorist and extremist” by the Russian government and convicted of several crimes, which he maintained were hollow and politically motivated.

Britain’s The Guardian notes his death “is likely to be seen as a political assassination attributable to Vladimir Putin”.

The prison service said Navalny “felt unwell after a walk” and “fainted and died quickly”. Medical workers were called and resucitation was attempted, without success, they said. They claimed Navalny had no prior health complaints and asserted an investigation would take place into the cause of death.

A nationalist, Navalny believed the best way to revive a strong Russia was by fighting economic and political corruption, which put him on a collision course with Vladimir Putin.

Criticism of Russia’s treatment of Navalny has poured in today. US Secretary of State Antony Blinken said the death “only underscores the weakness and rot at the heart of the system that Putin has built”, saying Russia is responsible. Britain’s Foreign Secretary Lord Cameron said the West should hold Putin accountable for the death, and that there should be consequences.

Russia itself has scoffed at the suggestions it was in any way responsible for the death of the political prisoner, their foreign affairs spokesman Maria Zakharova noting the claims of an assassination exposed foreign prejudice against Russia. She said despite a forensic examination not yet having taken place, Western leaders had already leaped to conclusions.

This story is developing, more follows.

TOPSHOT – Opposition leader Alexei Navalny appears on a screen set up at a courtroom of the Moscow City Court via a video link from his prison colony during a hearing of an appeal against his nine-year prison sentence he was handed in March after being found guilty of embezzlement and contempt of court, in Moscow on May 17, 2022. Alexei Navalny’s hearing comes as Russian authorities seek to silence remaining government critics and Moscow pushes on with its military campaign in neighbouring Ukraine, with thousands killed and some 10 million displaced. He is already serving two-and-a-half years in a prison some 100 kilometres (60 miles) east of Moscow for violating parole on old fraud charges. If his new sentence comes into force, the 45-year-old opposition politician will be transferred to a strict-regime penal colony, which will place him in much harsher conditions. The new sentence will replace the old one — that he was handed in February last year — meaning Navalny will remain behind bars for another eight years. (Photo by Kirill KUDRYAVTSEV / AFP) (Photo by KIRILL KUDRYAVTSEV/AFP via Getty Images)