Russia’s prison agency earlier said Navalny died on Friday in the Arctic penal colony where he was serving a 19-year sentence. The 47-year-old had crusaded against official corruption and staged massive anti-Kremlin protests as Putin’s fiercest foe.

Navlany’s team said it has not yet received direct confirmation of his death and had only seen a general announcement by the regional judicial authorities.

Yulia Navalnaya called upon the international community to come together and fight against the “horrific regime” in Russia, speaking at the Munich Security Conference on Friday in an appearance that was scheduled before the news of her husband broke.

In her speech, she expressed some doubt over the veracity of the news of her husband’s death.

“I don’t know whether we should believe the terrible news that we are receiving exclusively from Russian state sources,” said Yulia Navalnaya.

“We cannot believe Putin and Putin’s government,” she added. “They always lie.”

However, she called on the international community “to unite and fight evil”, and that Putin and his supporters would be held accountable soon.

Earlier, Navalny’s mother Lyudmila Navalnaya said her son had been “alive, healthy and happy” when she last saw him on February 12, according to Russian newspaper Novaya Gazeta.

“I don’t want to hear any condolences. We saw him in prison on [February] 12, in a meeting. He was alive, healthy and happy,” Navalnaya mother said in a Facebook post, according to the publication.

In his last public appearance before his reported death, Navalny spoke by videolink to a court on Thursday, Russian state media reported.

Navalny did not complain about his health and “spoke actively, presenting arguments in defence of his position”, a regional court from the city of Vladimir, to the east of Moscow, told the RIA news agency.

Separately Nikolaos Gazeas, a German lawyer for Navalny, told the daily Koelner Stadt-Anzeiger that he was stunned by the news of Navalny’s death after seeing images of him participating in the court hearing.

“He made a fit and strong impression as usual,” he said, adding that a Russian colleague had visited Navalny on Wednesday while another was currently on his way to his prison to learn more about the circumstances of his death.

‘Navalny has become immortal’

Meanwhile, other Putin opponents also reacted strongly to the news of Navalny’s death.

“There is nothing more the dictator can do to Navalny, Navalny is dead and has become immortal,” said Boris Akunin, a renowned Russian writer who lives in self-imposed exile in Europe.

“I also think that a murdered Alexey Navalny will be a bigger threat for the dictator than a living one. Most likely, to drown out voices of protest, [Putin] will launch a campaign of terror in the country,” he told AFP.

Russian Nobel Peace Prize winner Dmitry Muratov described Navalny’s death as “murder”.

“Alexey Navalny was tortured and tormented for three years. As Navalny’s doctor told me: the body cannot endure such things. Murder was added to Alexey Navalny’s sentence,” he was quoted as saying by the Novaya Gazeta newspaper.

Exiled Russian opposition politician Dmitry Gudkov said on social media, “Alexei’s death is a murder. Organised by Putin … Even if Alexei died of ‘natural’ causes, they were caused by his poisoning and further torture in prison.”

Bill Browder, a British American businessman who was once among the biggest foreign investors in Russia before becoming a fierce regime critic, said on X, “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 an alternative to kleptocracy and repression.”