Russian opposition leader Alexei Navalny poisoned with Novichok

Same nerve agent was used in UK attack on Russian former spy Sergei Skripal that was blamed on Moscow

The German government said Russian opposition activist Alexei Navalny was poisoned with the Soviet-era nerve agent Novichok. AP

The Russian opposition leader Alexei Navalny was poisoned with the same Soviet-era nerve agent that was used on a former spy in the UK, the German government has said.

New tests proved that Mr Navalny, one of Russian President Vladimir Putin’s most fierce critics, was poisoned with Novichok, according to the German government.

Mr Navalny, a politician and corruption investigator, fell ill on a flight to Moscow from Tomsk in Siberia on August 20. The plane made an emergency landing and he was taken to a hospital in the city of Omsk.

He was transferred two days later to Berlin's Charité hospital where doctors last week said initial tests indicated Mr Navalny had been poisoned.

Chancellor Angela Merkel’s spokesman, Steffen Seibert, said in a statement on Wednesday that testing by a special German military laboratory had now shown “proof without doubt of a chemical nerve agent from the Novichok group.”

“It is a dismaying event that Alexei Navalny was the victim of an attack with a chemical nerve agent in Russia,” Mr Seibert said. “The German government condemns this attack in the strongest terms.”

The nerve agent is a cholinesterase inhibitor, part of the class of substances that doctors at the Berlin hospital initially identified in Mr Navalny.

British authorities identified Novichok as the poison used in 2018 on Russian former spy Sergei Skripal and his daughter in England. He spent months in hospital but survived the attack.

More than 150 Russian diplomats were expelled from the United States, the EU and Nato countries in a show of support for Britain after the attempted killing on UK soil. The main suspects for the attack fled to Russia and remain there.

Germany demanded a response from the Russian government over the latest findings. The Kremlin said on Wednesday it hadn’t yet been informed of Mr Navalny being poisoned with a nerve agent.

“Such information hasn’t been relayed to us,” Kremlin spokesman Dmitry Peskov told the state Tass news agency.

Mr Seibert said the German government would inform its partners in the EU and Nato about the test results. He said that it would consult with its partners in light of the Russian reaction “on an appropriate joint response.”

Germany would also contact the Organisation for the Prohibition of Chemical Weapons, he added.

Mr Navalny’s allies in Russia have insisted he was deliberately poisoned by the country’s authorities, accusations that the Kremlin rejected as “empty noise”.

The Russian doctors who treated Mr Navalny in Omsk repeatedly contested the German hospital's poisoning conclusion, saying they had ruled out poisoning as a diagnosis and that their tests for cholinesterase inhibitors came back negative.

In Charité's latest update, the hospital said Mr Navalny was still in an induced coma but in a stable condition.