Russian opposition leader Alexei Navalny demanded Monday that Russia return the clothes he was wearing when he fell ill last month, saying the items are important evidence in the investigation of his poisoning.
Navalny became sick while flying to Moscow on Aug. 20 and was taken to a hospital in Omsk. He wrote in his blog Monday that before being sent to Germany for treatment two days later, his clothes were taken from him.
"Considering Novichok was found on my body, and that infection through contact is very likely, my clothes are a very important piece of evidence," he said.
A German military lab determined Navalny was poisoned with the nerve agent Novichok, a substance Western governments have accused Russia of using in the past, including against a former spy in Britain in 2018.
Russia has not opened an investigation into the incident involving Navalny, saying its labs have found no indications he was poisoned. The Kremlin has also denied any involvement.
Germany has threatened economic sanctions against Russia in response to what Foreign Minister Heiko Maas called a "serious crime," while British Prime Minister Boris Johnson called the use of a chemical agent "outrageous."
The Trump administration has said it is working with allies "to hold those in Russia accountable."
Doctors in Germany put Navalny under an induced coma for more than a week as part of his treatment. After waking up, Navalny has reported his condition improving, including regaining more of his mental and physical abilities.
Navalny has been a frequent critic of Russian President Vladimir Putin and worked on anti-corruption efforts in Russia. He has been jailed numerous times on charges that he and his supporters said were politically motivated.