London, Feb 17 : Russian President Vladimir Putin's foes and critics have often met with violent deaths at the very peak of their conflicts with the Kremlin leader during his nearly quarter-century in power, a media report said.

Alexei Navalny's death, which many foreign leaders and supporters say is murder, came after he was banished to an Arctic Circle prison, where he was regularly thrown in a punishment cell, exposed to the elements and significantly malnourished.

Putin's other foes have been targeted in diverse ways: shootings, poisonings and even a plane crash. Many of the deaths are never solved and remain listed as accidents and suicides, leaving open the question of just how many of his enemies Putin has dispatched with over the years, The Guardian reported.

A number of former members of the Russian intelligence services who defected to the west have been targeted in poisonings since 2000.

Putin's dark methods first came to international attention during the case of Alexander Litvinenko, a former member of the FSB security services who had become an opponent of Putin and died of polonium-210 poisoning in London in 2006. His killers, who both had links to the intelligence services, were accused of lacing his tea with a radioactive element, The Guardian reported.

The former head of the Wagner paramilitary group Yevgeny Prigozhin was on poor terms with Putin when he arrived in Moscow in August last year. He was there for talks with Putin after an aborted mutiny that saw his mercenaries seize the city of Rostov and march toward Moscow.

He appeared to have negotiated a truce with the Kremlin, agreeing to evacuate his troops to Belarus and focus on the group's activities outside Ukraine. But an explosion aboard his Embraer Legacy 600 business jet sent the plane spiralling to the ground, killing Prigozhin, the field commander Dmitry Utkin and eight others on board, The Guardian reported.

One of the most brazen killings of a Putin critic was the 2015 shooting of Boris Nemtsov, an opposition leader who had served as deputy prime minister under Boris Yeltsin and was seen as a potential successor.

Nemtsov was shot four times in the back by an unknown assailant within view of the Kremlin. Five men of Chechen origin were arrested over the attack, but those close to Nemtsov believed the Kremlin was directly involved, The Guardian reported.

Anna Politkovskaya, the journalist, who had reported critically of Putin and of the Chechen leader, Ramzan Kadyrov, was shot in her apartment building in Moscow in 2006.

There also have been reports of prominent Russian executives dying under mysterious circumstances, including apparent suicides or falls from great heights, The Guardian reported.

In 2013, Boris Berezovsky was found apparently hanged in the bathroom of his Ascot home. Berezovsky was a former Kremlin insider turned vocal critic of Putin's government who went into self-imposed exile in the UK in the early 2000s, The Guardian reported.

Many of Berezovsky's associates have also died in mysterious circumstances, including Badri Patarkatsishvili, a Georgian oligarch and business partner, and Nikolai Glushkov and the Yukos oil founder, Yuri Golubev, who were found dead in London.

/IANS