Reuters
The Daily Beast reports that before his death, Lesin was considering making a deal with the FBI to protect himself from corruption charges. 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.
Lesin isn't the only person linked to Putin's government that has died in violent or mysterious circumstances. Here are some of the other people Putin is suspected of assassinating:
Alexander Litvinenko
via The Telegraph
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.
Anna Politkovskaya
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."
Mark Wilson/Getty Images
Mark Wilson/Getty Images
Natalia Estemirova
Natalia Estemirova was a journalist who sometimes worked with Politkovskaya. She specialised in uncovering human rights abuses carried out by the Russian state in Chechnia.
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
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.
Alex Wong/Getty Images
Alex Wong/Getty Images
Boris Nemtsov
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
Boris Berezovsky
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.
Graeme Robertson/Getty Images
Graeme Robertson/Getty Images
Paul Klebnikov
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.
Sergei Yushenkov
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 organisation Liberal Russia had been recognised by the Justice Ministry as a party.