ALSO SEE: Another Putin Critic Dies After Falling Out a Window

Here's a list of people who have been critical of Putin and the Russian president is suspected of assassinating:

Pavel Antov - December 2022

Russian tycoon reportedly fell from a hotel window in Rayagada, India, on December 25 days after his 65th birthday.

The politician and millionaire criticized Putin's war with Ukraine following a missile attack in Kyiv earlier this year on WhatsApp but quickly deleted the message and claimed that someone else wrote it, the BBC reported.

"Our colleague, a successful entrepreneur, philanthropist Pavel Antov passed away," Vice Speaker of the Regional Parliament Vyacheslav Kartukhin said on his Telegram channel, Russian media outlet TASS reported. "On behalf of the deputies of the United Russia faction, I express my deep condolences to relatives and friends."

Ravil Maganov - September 2022

Lukoil chairman Ravil Maganov had been openly critical of Russia's invasion of Ukraine, CNBC reported. Shortly after the war began, the oil company called for "the soonest termination of the armed conflict," per the report.

Maganov, similar to Antov, died mysteriously by falling out the window of a Moscow hospital in September, the outlet reported. However, a now-deleted statement from Lukoil said that the 67-year-old died "following serious illness."

Dan Rapoport- August 2022

Businessman Dan Rapoport publicly condemned the Russia-Ukraine war on social media multiple times and emphasized his support for Ukraine, the Daily Beast reported.

He was discovered dead in front of an apartment building in Washington, D.C, in August, according to the report. Police said he had a Florida driver's license, a black hat, just over $2500, and orange flip-flops when he was found.

Mikhail Lesin- November 2016

Russian press minister Mikhail Lesin was found dead of "blunt force trauma to the head" in a Washington, DC, hotel room in November 2015.

Lesin, who founded the English-language television network Russia Today (RT), was considering making a deal with the FBI to protect himself from corruption charges before his death, per The The Daily Beast.

For years, Lesin had been at the heart of political life in Russia and would have known a lot about the inner workings of the rich and powerful.

Alexander Litvinenko- November 2006

Alexander Litvinenko was a former KGB agent who died three weeks after drinking a cup of tea at a London hotel that had been laced with deadly polonium-210.

A British inquiry found that Litvinenko was poisoned by FSB agents Andrei Lugovoi and Dmitry Kovtun, who were acting on orders that had "probably approved by Mr Patrushev and also by President Putin."

Litvinenko was very critical of Putin, accusing him of, among other things, blowing up an apartment block and ordering the murder of journalist Anna Politkovskaya.

Boris Nemtsov- February 2015

Boris Nemtsov was a former deputy prime minister of Russia under Boris Yeltsin who went on to become a big critic of Putin — accusing him of being in the pay of oligarchs.

He was shot four times in the back just yards from the Kremlin as he walked home from a restaurant. Despite Putin taking "personal control" of the investigation into Nemtsov's murder, the killer has not been found.

Boris Berezovsky- March 2013

Boris Berezovsky was a Russian oligarch who fled to Britain after he fell out with Putin. During his exile he threatened to bring down Putin by force. He was found dead at his Berkshire home in March 2013 in an apparent suicide, although an inquest into his death recorded an open verdict.

Berezovsky was found dead inside a locked bathroom with a ligature around his neck. The coroner couldn't explain how he had died.

The British police had, on several occasions, investigated alleged assassination attempts against him.

Natalia Estemirova- July 2009

Natalia Estemirova was a journalist who sometimes worked with Politkovskaya.

She specialized in uncovering human-rights abuses carried out by the Russian state in Chechnya.

She was abducted from outside her home and later found in nearby woodland with gunshot wounds to her head. No one has been convicted of her murder.

Stanislav Markelov and Anastasia Baburova- January 2009

Human-rights lawyer Stanislav Markelov represented Politkovskaya and other journalists who had been critical of Putin.

He was shot by a masked gunman near the Kremlin. Journalist Anastasia Baburova, who was walking with him, was also shot when she tried to help him.

Anna Politkovskaya- October 2006

Anna Politkovskaya was a Russian journalist who was critical of Putin. In her book "Putin's Russia," she accused Putin of turning his country into a police state. She was murdered by contract killers who shot her at point-blank range in the lift outside her flat.

Five men were convicted of her murder, but the judge found that it was a contract killing, with $150,000 paid by "a person unknown."

Paul Klebnikov- July 2004

Paul Klebnikov was the chief editor of the Russian edition of Forbes. He had written about corruption and dug into the lives of wealthy Russians.

He was killed in a drive-by shooting in an apparent contract killing, according to the Committee to Protect Journalists.

Sergei Yushenkov- April 2003

Sergei Yushenkov was a Russian politician who was attempting to prove the Russian state was behind the bombing of an apartment block.

He was killed in an assassination by a single shot to the chest just hours after his political organization, Liberal Russia, had been recognized by the Justice Ministry as a party, the BBC reported.