A court in Moscow has issued an arrest warrant for the widow of Russian opposition leader Alexei Navalny on charges of extremism, according to state media.

The charges brought against Yulia Navalnaya, who lives outside Russia, in absentia are to do with her alleged “participation in an extremist society”, Tass news agency said.

Navalny was Russia’s most significant opposition leader of the past decade. He died in February in an Arctic Circle jail. Russian authorities said he died of natural causes – but his widow said Navalny had been “tortured, starved, cut off and killed” by Russia’s president Vladimir Putin.

Navalny had been serving 19 years on extremism charges that were widely seen as politically motivated.

Responding to the arrest warrant against her, Yulia Navalnaya posted on X: “When you write about this, please do not forget to write the main thing: Vladimir Putin is a murderer and a war criminal.

“His place is in prison, and not somewhere in The Hague, in a cosy cell with a TV, but in Russia – in the same colony and the same two-by-three-metre cell in which he killed Alexei.”

The Moscow court ruled that Ms Navalnaya, who has vowed to continue the work of her husband, should be remanded in custody and she was declared wanted.

The decision means she would face arrest if she set foot in Russia.

The charges may be linked to a Moscow court ruling in June 2021 which outlawed three organisations linked to Navalny, labelling them “extremists”.

Ms Navalnaya was unable to attend his funeral in March.

She has since met a number of Western leaders, including US President Joe Biden.

This month, she was elected to chair the US-based Human Rights Foundation – a non-profit organisation working to promote and protect human rights across the world.

She said she would use her role to step up the struggle her husband fought against Mr Putin.