The Kremlin has been forced to deny that Vladimir Putin died of cancer at his Valdai residence north of Moscow on Thursday.
The Russian leader has been subject to online speculation about his health, with the Kremlin also denying online rumours that he had suffered a heart attack.
The claims were made by Telegram channel General SVR, which has long claimed the 71-year-old is suffering from cancer.
The channel claimed that Putin’s entourage sought to pass off his body double as the real president.
The claims were rejected by Putin’s spokesman Dmitry Peskov, who told state media RIA Novosti that the report was an “absurd information canard”.
The post by the Telegram channel read: “Attention! There is currently an attempted coup in Russia! Russian President Vladimir Putin died this evening at his residence in Valdai. At 20.42 Moscow time, doctors stopped resuscitation and pronounced death.
“Now the doctors are blocked in the room with Putin’s corpse, they are being held by members of the presidential security service on the personal orders of Dmitry Kochnev who is in touch and receives instructions from the Secretary of the Security Council of the Russian Federation Nikolai Patrushev.
“Security for the president's double has been beefed up. Active negotiations are underway. Any attempt to pass off a double as the president after Putin’s death is a coup.”
The account, while popular in Russia, is anonymous and does not provide evidence for its claims.
Mr Peskov said: “These [kinds of stories] belong to the category of fake news, discussed with enviable tenacity by a number of media outlets. This brings nothing but a smile [in the Kremlin].”
Earlier this year, the spokesperson addressed speculation about doppelgängers, calling them “lies”.
“Perhaps you had heard that Putin has multiple doubles, who work instead of him while he is sitting inside a bunker,” he said.
“This is yet more lies. This is one more lie. You see our president. He is just as he used to be, mega-active.”
On Wednesday evening, Putin was seen overseeing a nuclear military drill, which it said involved delivering a “response to an enemy nuclear strike".
State television showed Putin directing the exercise on a video call with top military officials.
On Friday, photos were released by state-owned news agency Sputnik of Putin chairing a meeting with Security Council permanent members via video link from Moscow.
