At least six prominent Russian businessmen have died in a string of apparent suicides within the last four months.
According to CNN, three of the men allegedly also killed family members before taking their own lives. Four of them were associated with Russian government-owned energy giant Gazprom or one of its subsidiaries.
Well, it’s not the first time there have been reports about Russian officials dying suspiciously, and Russian President Vladimir Putin has long been known to take extreme measures to silence his opponents.
Here’s a list of every Russian oligarch we know about that has died this year:
- On April 18, Vladislav Avayev and his wife and daughter were found dead in their Moscow apartment, according to TASS, a Russian state-controlled news agency.
- Preliminary evidence suggested that the deaths were the result of a murder-suicide, TASS reported. Avayev was found inside his multimillion-dollar Moscow apartment holding a pistol, which was presumably used to kill his wife and 13-year-old daughter.
- Avayev was the former vice president of Gazprombank, which is Russia’s third-largest bank, and services energy giant Gazprom.
- Just two days later, another high-profile Russian was found dead in shockingly similar circumstances.
- The body of Sergey Protosenya, a former executive at Novatek—Russia’s largest independent natural gas producer—was found hanged outside the Spanish villa he and his family were renting. His wife and 18-year-old daughter were found stabbed to death in their beds, according to Spanish news station Telecinco.
- Protosenya, 55, accumulated a net worth of more than $433 million, according to Telecinco.
- Last month, Russian billionaire Vasily Melnikov was also found dead in his multimillion-dollar apartment in the Russian city of Nizhny Novgorod alongside his wife and two sons, according to Russian newspaper Kommersant and reported by Newsweek.
- All three Melnikovs died from stab wounds. According to Kommersant, police investigations determined that Melnikov killed his wife and sons before committing suicide.
- Melnikov was an executive at the medical firm MedStom. The company has suffered immensely as a result of the economic sanctions placed on Russia in the aftermath of the country’s invasion of Ukraine, according to Ukrainian news outlet Glavred and reported by Newsweek.
- In late February, just days after Russia officially invaded Ukraine, Mikhail Watford was found hanged in the garage of his Surrey, U.K., home. His wife and children were home at the time, although they were unharmed.
- The Ukrainian-born Russian, 66, made his millions as an oil and gas tycoon after the fall of the Soviet Union, according to the BBC.
- Born with the last name Tolstosheya, Watford changed his name after moving to the U.K. His death is under investigation by Surrey Police, who told the BBC in early March that “there were not believed to be any suspicious circumstances at the time.”
- On February 25, just three days before Watford’s death, former Gazprom executive Alexander Tyulyakov, 61, was found hanged in the garage of his apartment building near St. Petersburg, according to Russian newspaper Gazeta and reported by Newsweek.
- Police told Gazeta that they found a suicide note next to his body, which led investigators to believe he died by suicide.
- Tyulyakov’s suicide is currently being investigated by Gazprom, whose security units arrived at the scene with police in February, according to Gazeta.
- Like Tyulyakov, Leonid Shulman was a top executive at Gazprom when he was found dead by apparent suicide in January, before Russia had invaded Ukraine.
- Shulman, 60, similarly was found next to a note that led police to believe he committed suicide, according to the Gazeta and reported by Newsweek.
- Shulman’s death came just months after a probe into his alleged fraud at Gazprom was opened, according to Fortune. According to a note from the Warsaw Institute, Gazprom is also currently investigating Shulman’s death.
- Gazprom, Novatek, and Medstom did not immediately respond to Fortune’s requests for comment.