Roman Abramovich reportedly gave Putin a handwritten note from Ukraine's president Zelensky, prompting a savage reply from the Russian leader.
It comes after reports the Chelsea FC owner has been flying between Moscow and Kyiv to relay messages between Putin and Zelensky.
After relaying a message to Putin about potential terms of a peace agreement, Putin reportedly told Abramovich 'tell him I will thrash them'.
Last week, the Kremlin has confirmed outgoing Chelsea owner was involved in early peace talks following the Russian invasion of Ukraine, reports the Mail Online.
President Vladimir Putin ordered his troops into the neighbouring country in late February, starting a bloody conflict which has been condemned by the vast majority of countries around the world.
The war in Ukraine led to heightened scrutiny of Russians living in the United Kingdom on so-called 'Golden Visas'.
Abramovich was one such oligarch with assets worth billions in the UK, so claims he was playing a part in initial peace negotiations were met with surprise.
Those reports were not backed up by Russian government officials at the time but a Kremlin spokesperson has now confirmed the 55-year-old was involved.
"He did take part at the initial stage," Dmitry Peskov, Putin's press secretary, said of Abramovich on Thursday. "Now the negotiations are between the two teams, the Russians and Ukrainians."
Abramovich's mother, Irina, was born in Ukraine and his daughter, Sofia, has posted on social media to declare it is only Putin who "wants a war with Ukraine".
A spokesperson for the Chelsea owner - who bought the club in 2003 and is now selling up - released a statement four days after Putin's invasion which said: "I can confirm that Roman Abramovich was contacted by the Ukrainian side for support in achieving a peaceful resolution, and that he has been trying to help ever since.
"Considering what is at stake, we would ask for your understanding as to why we have not commented on neither the situation as such nor his involvement. Thank you."
Abramovich's role in the early peace talks was also confirmed by Ukrainian film director and producer Alexander Rodnyansky, who said: "I can confirm that the Ukrainian side have been trying to find someone in Russia willing to help them in finding a peaceful resolution
"They are connected to Roman Abramovich through the Jewish community and reached out to him for help. Roman Abramovich has been trying to mobilise support for a peaceful resolution ever since.
"Although Roman Abramovich's influence is limited, he is the only one who responded and taken it upon himself to try. If this will have an impact or not, I don't know, but I am in contact with Zelensky's staff myself, and know that they are grateful for his genuine efforts."
Russian officials have also hit back at Joe Biden ’s jibe that “butcher” Vladimir Putin “cannot stay in power” by branding the US leader “weak, sick and deluded”.
Moscow deployed its loyal attack dogs on Kremlin-controlled TV to claim the US leader should undergo a “medical examination” because he is incapable of “soberly” assessing reality.
Putin’s own spokesman Dmitry Peskov said: "We don't know what President Biden meant, we know what he said.
“And what he said in general in his speech suggests that he is a victim of numerous delusions.”
Speaker of the Russian parliament Vyacheslav Volodin branded Biden a “weak and sick man”, guilty of “hysteria” by branding Putin a “butcher” for the bloodshed in Ukraine.
He said: "The US president’s behaviour might be “professionally explained by psychiatrists” but “from a male point of view, the weak behave this way.
“US citizens should be ashamed of their president.
“Perhaps, he is sick. It would be right for Biden to undergo a medical examination.”
