The Russian leader has grabbed headlines once again after British Prime Minister Theresa May accused his country of poisoning double-agent Sergei Skripal.
But it was another similar incident several years ago that sparked a terrifying threat from Putin.
The Kremlin were blamed for the death of Russian defector Alexander Litvinenko in 2006, in London.
They have repeatedly denied the claims but the accusations created tensions in Russia.
It led to Putin warning his ally Mikheil Saakashvili – who served as the President of Georgia between 2004-2013 – to cut ties with the West.
“He took me aside, in a dark room without witnesses,” Saakachvili recalled in BBC 2’s documentary on Putin, which aired last week.
“We sat on the chairs and he put his hand on my knee with his nails.
“Looking straight in my eyes, he said: ‘You are really underestimating us’.
“You cannot play around with Russia like this’.”
A still image taken from an undated video shows Sergei Skripal, a former colonel of Russia’s GRU military intelligence service, being detained by secret service officers
As police still try to figure out how Skripal and his daughter were poisoned in Salisbury, the Kremlin branded allegations Russia were responsible as “nonsense”.
Putin even smirked at reporters when he was asked about his country’s involvement.
Putin: The New Tsar is available to watch on BBC iPlayer now.