TOMSK, Russia -- Seven local lawmakers of the Siberian city of Tomsk have called on Russia's Investigative Committee to launch a probe into the nerve-agent poisoning in August of Russian opposition politician Aleksei Navalny.
The city legislators said in an official letter to the Investigative Committee that they are concerned about the possible use of "a chemical poison in our city...with the state's participation."
The letter was made public on December 17 in a Twitter post by Tomsk City Duma member Ksenia Fadeyeva.
The letter says data collected by independent investigative journalists, as well as the conclusions of experts at European laboratories who tested medical samples from Navalny, provide enough evidence to launch an investigation.
The local lawmakers stressed that since the names of individuals allegedly involved in Navalny's poisoning have been made public, the investigation must be launched immediately.
The letter appeared on Twitter hours after Russian President Vladimir Putin claimed that Navalny "is supported by the U.S. secret services."
Putin said that is why Russia's secret services "must keep an eye on him, but it does not mean that it is necessary to poison him."
"Who needs him? If they wanted to, they would have finished the job,” Putin said.
The 44-year-old Navalny was airlifted to Germany in August after falling ill during a flight from Tomsk to Moscow.
Laboratory tests in three European countries, confirmed by the global chemical weapons watchdog, established that Navalny was poisoned with a Soviet-style Novichok nerve agent.
Some earlier investigative reports concluded that Navalny was most likely poisoned before he boarded the plane in Tomsk.
Russia has rejected previous calls for an investigation into the poisoning and denies the involvement of state agents in the case -- saying it has yet to be shown any evidence.
A report issued on December 14 by the British-based open-source investigative group Bellingcat published the names and photos of FSB operatives accused of taking part in a state-backed poisoning operation.
The report, which includes a timeline of events around the attack on Navalny, was prepared jointly by Bellingcat, The Insider, Der Spiegel, CNN, and a Russian investigative website.
Navalny has said that such an operation could not have been implemented without direct orders from Putin and Aleksandr Bortnikov, the head of Russia's Federal Security Service (FSB).
Russian Foreign Minister Sergei Lavrov described the reports about possible FSB involvement in the poisoning as "funny."
Putin's spokesman Dmitry Peskov canceled his daily briefings on December 15-16 after the Bellingcat report was published, citing preparations for Putin's annual press conference.
Earlier in the week, three lawmakers in St. Petersburg and two lawmakers from Russia's northwestern city of Pskov also officially demanded that Investigative Committee chief Aleksandr Bastrykin launch an investigation into Navalny's poisoning.