MOSCOW (AFP) - Russian opposition leader Alexei Navalny claimed on Monday (Dec 21) that he had tricked a security agent into admitting that the FSB domestic intelligence agency sought to kill him this summer and placed poison into his underwear.
In a bombshell blog post, the Kremlin critic said he called a man called Konstantin Kudryavtsev, claiming he was a chemical weapons expert with the Federal Security Service.
"I called my killer. He confessed everything," Mr Navalny said on Twitter.
Mr Navalny said he disguised his phone number and presented himself as an aide to Security Council chief Nikolai Patrushev, explaning he needed information for an official report on the attempted poisoning.
He did not provide any proof of his claims, saying a voice analysis "would demonstrate that it is indeed" Kudryavtsev.
Apart from the blog post the opposition leader published an audio recording and a transcript of the phone call and released a video of him conducting the conversation.
In the audio recording, the voice initially sounds hesitant and cautious but eventually justifies why Mr Navalny managed to survive.
There were no immediate reactions from the Russian authorities.
Mr Navalny, 44, fell violently ill during a flight from Siberia to Moscow in August and was hospitalised in the Russian city of Omsk before being transported to Berlin by medical aircraft.
A joint media report led by the Bellingcat investigative website last week revealed what it said were the names and photos of chemical weapons experts from the FSB that had tailed Mr Navalny for years.
President Vladimir Putin last week rejected the report, saying if Russia's security services were behind Mr Navalny's poisoning he would be dead.
In his blog post on Monday, Mr Navalny said that last week he called the security agents identified in the report. He said nearly all hung up on him except the man he said was Kudryavtsev.
During their call, Kudryavtsev said his unit had not expected the pilot to make an emergency landing in Omsk.
He said that if the flight had been allowed to continue, Mr Navalny would not have survived.
The agent said the attacker had placed the poison in the inside of one of Mr Navalny's underpants.
He also detailed how he and another FSB agent flew to Omsk to take care of Mr Navalny's clothing and removed any trace of the poison.
However, Kudryavtsev never explained his exact role in the operation.
Der Spiegel as well as Bellingcat and Russian website The Insider were given access to Mr Navalny's account and published reports on Monday too.