Lukoil Chairman Ravil Maganov is the 8th Russian energy executive to die suddenly this year

WASHINGTON — The death of Ravil Maganov, chairman of Russian oil giant Lukoil, at a hospital in Moscow appears to mark the eighth time this year that a Russian energy executive has died suddenly and under unusual circumstances.

Maganov died Thursday after falling out of a window of the capital's Central Clinical Hospital, according to the Russian state-sponsored news outlet Interfax. The circumstances of Maganov's death were confirmed by Reuters, citing two anonymous sources. The oil company, and its chairman, had been critical of the Ukraine war, expressing disapproval in a statement on March 3.

But Lukoil, the company that Maganov helped to build, said the 67-year-old had "passed away following a serious illness" in a press statement. The Russian Embassy in Washington did not respond to a request from CNBC for an official statement.

The circumstances surrounding Maganov's sudden death have drawn international attention, in part, because seven other top Russian energy executives have been victims of untimely deaths since January, according to reports by Russian and international news agencies.

Below is a list of these cases, in chronological order.

In late January, Leonid Shulman, a top executive at Russian natural gas giant Gazprom, was found dead in the bathroom of a cottage in the village of Leninsky. The Russian media group RBC reported his death, but did not cite a cause.On Feb. 25, another Gazprom executive, Alexander Tyulakov, was found dead in the same village as Shulman, this time in a garage. According to the Russian media outlet Novaya Gazeta, investigators found a note near Tyulakov's body.On Feb. 28, three days after Tyulakov died, a Russian oil and gas billionaire living in England, Mikhail Watford, was found hanged in the garage of his country estate. At the time, investigators reportedly said Watford's death was "unexplained," but did not appear suspicious.On April 18, a former vice president of Gazprombank, Vladislav Avayev, was found dead in his Moscow apartment, alongside his wife and daughter, who also died. Authorities treated the case as a murder-suicide, Radio Free Europe reported at the time. Gazprombank is Russia's third-largest bank and has close ties to the energy sector.On April 19, a former deputy chairman of Novatek, Russia's largest liquefied natural gas producer, was found dead in a vacation home in Spain. Like Avayev in Moscow, Sergei Protosenya was found with his wife and daughter, who were also deceased. And like Avayev, police investigating the scene said they believed it was a murder-suicide, a theory that Avayev's surviving son has publicly rejected.In May, the body of billionaire and former Lukoil executive Alexander Subbotin was discovered in the basement of a country house in the Moscow region. The room where Subbotin died was allegedly used for "Jamaican voodoo rituals," Russian state media outlet TASS reported, quoting local authorities.In July, Yury Voronov, founder and CEO of a shipping contractor that services Gazprom's Arctic projects was found dead of an apparent gunshot wound in a swimming pool at his home in Leninsky, the same elite St. Petersburg gated community where Shulman and Tyulakov died earlier in the year.