MOSCOW • The nerve agent used to poison Russian opposition leader Alexei Navalny was detected on an empty water bottle from his hotel room in the Siberian city of Tomsk, suggesting he was poisoned there and not at the airport as first thought, his team said yesterday.

Mr Navalny fell violently ill on a flight in Russia last month and was airlifted to Berlin for treatment. Laboratories in Germany, France and Sweden have established he was poisoned by a Novichok nerve agent, a poison developed by the Soviet military, though Russia denies this and says it has seen no evidence.

A video posted on Mr Navalny's Instagram account showed members of his team searching the room he had left in the Xander Hotel in Tomsk on Aug 20, an hour after they learnt he had fallen sick in suspicious circumstances.

"It was decided to gather up everything that could even hypothetically be useful and hand them to the doctors in Germany," the post said.

The video shows two water bottles on a desk, and another on a bedside table. Mr Navalny's team, wearing protective gloves, are seen placing items into blue plastic bags.

"Two weeks later, a German laboratory found traces of Novichok precisely on the bottle of water from the Tomsk hotel room," the post said. "And then more laboratories that took analyses from Alexei confirmed that that was what poisoned Navalny."

Previously, Mr Navalny's aides had said they suspected he had been poisoned with a cup of tea he drank at Tomsk airport.

Mr Vladimir Milov, a former energy vice-minister and an ally of Mr Navalny, said his team had outmanoeuvred the police with their quick thinking: "They took the evidence from under their noses and shipped it out of the country."

Mr Navalny is the most prominent political opponent of President Vladimir Putin. His investigations of official corruption, published on YouTube and Instagram, have reached audiences of many millions across Russia.

REUTERS