From plane crash to poisonings, Vladimir Putin's critics have often met with violent deaths at the very peak of their conflicts with the Russian leader
Here's a look at some of the high-profile deaths involving those who have criticised Mr Putin over the years
Jailed Russian opposition figure and outspoken Kremlin critic Alexei Navalny died on Friday at the age of 47 in an Arctic Circle jail
Image: Reuters
Yevgeny Prigozhin, former head of the Wagner paramilitary group, died last year in a plane crash, two months after he led a failed mutiny against Russia's Ministry of Defence
Image: Reuters
Boris Nemtsov, a vocal Kremlin critic who was a deputy prime minister in the late 1990s under President Boris Yeltsin, was gunned down in February 2015 in Moscow
Image: Reuters
Boris Berezovsky, once a powerful Russian businessman turned exile living in England, was found dead in 2013 with a noose around his neck
Image: x/@Maytechummia
Alexander Litvinenko, a former Russian spy turned Kremlin critic, was fatally poisoned with polonium-210 in London in 2006
Ravil Maganov, chairman of Lukoil, died in a suspicious fall from a Moscow hospital window after openly criticising the war in Ukraine
Image: Reuters
Anna Politkovskaya was a vocal critic of Russia's war in Chechnya. She was gunned down in the entrance of her Moscow apartment in October 2006
Image: x/@vmarkov
Sergei Magnitsky, a Russian tax adviser who exposed corruption, was detained without a trial and died in prison days before he was set to be released
Image: forpeaceandfreedom.org
Alexander Perepilichnyy, a financier turned whistleblower, died in 2012 under murky circumstances in the UK