Undercover members of Russian's Federal Security Service (FSB) were involved in the poisoning of opposition figure Alexei Navalny, a new investigation has found.
Kremlin critic Navalny fell ill on a flight from Tomsk to Moscow on August 20. He was later transferred to a clinic in Berlin for treatment.
In September, the German government said there was "unequivocal proof of a chemical nerve agent from the Novichok group" in his body.
Russia has repeatedly denied any responsibility for Navalny's poisoning, stating that no Novichok agent was found in his body when he was treated in Omsk. Moscow has also said that any accusations against them are part of a wider Western campaign.
But the report led by the investigative website, Bellingcat, is the first time that named individuals have been implicated in the attempted killing of Navalny.
Bellingcat also says that Navalny had been under "years of surveillance" since he first announced his attention to run for president of Russia in 2017.
The report cited 37 trips since 2017 during which Navalny was followed by one or more of the named agents.
"Bellingcat and its partners also uncovered data pointing to the existence of a clandestine chemical weapons programme operated by members of Russia’s domestic intelligence services," the website said.
Three undercover members from this clandestine unit were found to have travelled alongside Navalny to Tomsk at the time he fell ill.
"These operatives were in the vicinity of the opposition activist in the days and hours of the time-range during which he was poisoned with a military-grade chemical weapon," Bellingcat reported. At least five other FSB employees supported the mission, they added.
Citing telecoms and travel records, Bellingcat also says that the poisoning was likely "mandated at the highest echelons of the Kremlin".
"Given this implausible series of coincidences, the burden of proof for an innocent explanation appears to rest purely with the Russian state."
The investigation does not establish that any of these agents were in direct contact with Navalny, nor that any action was taken or order given.
Euronews has contacted the FSB and Russia's Interior Ministry for a statement on the Bellingcat findings, which they are likely to dismiss.
Last month, Russia’s foreign minister, Sergei Lavrov, suggested Navalny may have been poisoned on the plane to Germany, or once he arrived in Berlin.
Following its publication, Navalny himself stated on Twitter that "the case concerning my murder attempt is solved".
"We know the names, we know the job ranks, and we have the photos," the opposition figure added.
How the investigation was carried out
The new study was led by Bellingcat, in collaboration with CNN, Der Spiegel, The Insider, and El Pais, and analysed "voluminous" telecommunications and travel data.
Aric Toler, the head of research at Bellingcat, told Euronews there is a wealth of data that is being sold and traded across Russia, such as passenger information for flights, phone records, and passport details.
"The Russian data black market is vast, you can buy and acquire almost any kind of information you can imagine," said Toler.
"We can access these data markets online very easily, such as through bots on popular messaging services like Telegram, which provided us with so much information.
"Russia has very loose private restrictions in both legislation and practices, and also has vast data collection on citizens."
The investigation also worked directly with Navalny and was provided with the opponent's personal travel history, which they used alongside dozens of leaked databases the website acquired in recent years.
Aric Toler told Euronews their first hypothesis was that a team of agents had trailed Navalny across Russia immediately before he was poisoned.
"We looked for flights that matched the itinerary of Navalny, travelling to and from Novosibirsk and Tomsk, two different cities, 200 to 300 kilometres apart.
"We found three people, one a real person and two who had nothing about them online, no taxpayer number, no residential history, no vehicle registration ... they were ghosts."
"We found that these two people were fake identities ... Once we had these suspicious names, we found that they all worked for the FSB and some were also experts in chemical weapons like Novichok."
Toler added that their suspicions were founded given the specificity of the travel itinerary and the decreased number of passengers on internal flights during the COVID-19 pandemic.
Bellingcat's investigations found that members of the undercover FSB unit also communicated with each other throughout the trip to Tomsk, with sudden peaks of communication just before the poisoning and during the night-time hours when Navalny left his hotel and headed to Tomsk airport.
Additionally, location data showed that one member was just a few minutes walk away from Navalny's hotel in the Siberian city that night.
"We don't have the psychic energy to say who said what and what the conversations were, but we know who called who, and the chronology of this," Toler told Euronews.
"It's clear high levels of the FSB were consistently being informed about the operation."
'The data is pretty clear'
The investigation also found that operatives may have tried to poison Navalny in July when at least two of the operatives were found to have tailed the Kremlin critic to Kaliningrad, where he was spending a weekend with his wife, Yulia. This had not been previously revealed by Navalny or any investigation.
"During this trip, Yulia Navalny also became sick with symptoms similar to a low-grade of Novichok," Toler told Euronews.
Bellingcat says that their investigation was important due to the "legal vacuum" around the case, as only Russia has offered jurisdiction for an official investigation into Navalny's near-fatal poisoning.
Foreign governments may now be able to follow up on Bellingcat's reports of Russia's repeated use of banned chemical weapons, despite their signature on international treaties.
"Any use of chemical weapons is serious and cannot be without consequences," the Organisation for the Prohibition of Chemical Weapons said in a statement.
Bellingcat also confirmed that they had not received a response from Russian authorities at the time of publication.
"The data is pretty clear", Aric Toler told Euronews. "It is important to say that for every source of data we find, we are sure to verify and corroborate it with other data sources."
"We have thousands upon thousands online of telecoms data and travel history that implicates this FSB team in the attempt of Alexei Navalny's life."
Bellingcat previously published the names of the Russian military intelligence (GRU) operatives they believe responsible for the Novichok poisoning of former double agent, Sergei Skripal in 2018. Moscow has still denied the accusations.