Russian opposition politician Alexei Navalny has shared a photograph from a Berlin hospital, sitting up in bed and surrounded by his family, and says he can now breathe independently following his poisoning last month.

The photo, which is the strongest evidence yet of Mr Navalny’s advancing recovery since he fell violently sick in Siberia on August 20, was swiftly followed by confirmation on Tuesday from his media spokeswoman that he planned to return to Russia.

“Hi, this is Navalny. I miss you all,” he wrote in the caption to his Instagram followers.

“I can still hardly do anything, but yesterday I could breathe all day on my own. Actually on my own.”

Mr Navalny, the leading opponent of Russian President Vladimir Putin, fell violently sick in Siberia last month and was flown to Berlin and treated at Charite hospital.

Germany says laboratory tests in three countries have determined he was poisoned with a Novichok nerve agent, and Western governments have demanded an explanation from Russia.

Moscow has called the accusations groundless.

The Navalny family in Berlin’s Charite Hospital on Tuesday. Photo: Instagram

Kremlin spokesman Dmitry Peskov reiterated on Tuesday that Moscow was open to clearing up what happened to Mr Navalny, but it needed access to information on his case from Germany.

He said Moscow did not understand why, if French and Swedish laboratories had been able to test his medical samples, Russia was not being given the same access.

The case has put further strain on relations between Russia and the West, already at a post-Cold War low since Moscow’s annexation of Crimea from Ukraine in 2014 and the attempted poisoning of former Russian double agent Sergei Skripal and his daughter with the same Novichok nerve agent in England in 2018.

German Chancellor Angela Merkel has faced calls to punish Russia by suspending work on a Nord Stream 2, a nearly completed pipeline bringing gas from Russia to Germany.

The photograph showed Mr Navalny sitting up in bed and looking towards the camera, with his wife Yulia supporting him with her arms and their two children looking on.

The New York Times on Tuesday quoted a German security official as saying Mr Navalny had spoken to a German prosecutor about the attempt on his life and said he planned to return to Russia as soon as he recovered.

Confirming the report, Mr Navalny’s spokeswoman Kira Yarmysh wrote on Twitter: “No other options were ever considered.”

Mr Peskov had said earlier on Tuesday: “Any citizen of the Russian Federation is free to leave Russia and return to Russia. If a citizen of the Russian Federation recovers his health, then of course everyone will be happy about that.”