A Russian oil tycoon was found dead after reportedly being treated with toad venom to cure a hangover

• Former oil exec Alexander Subbotin was found dead over the weekend, according to Newsweek and Russian media outlets.
• TASS, a state-owned news agency, said that he was discovered in a shaman's home in Mytishchi.

Russian media outlets reported that an oil tycoon was found dead over the weekend at the house of a shaman, according to Newsweek.

TASS, a state-owned news agency, said that he was discovered in a shaman's home in Mytishchi, and authorities are investigating, Newsweek reported.

The Moscow Times, an independent Russian news site, also reported on the topic.

Per TASS, it seemed that he suffered from a heart attack, and a source told the Russian outlet that he was highly intoxicated when he showed up at the house, Newsweek noted.

Another source, telegram channel Mash—though this has not been verified by police, Newsweek noted—said that he was there to get a hangover cure in the form of toad venom, having been friendly with the shaman and his wife for some time, The Independent reported.

Alexander Subbotin used to be high up at Lukoil, Newsweek and others have reported.

Lukoil is the country's second-largest oil producer, according to Reuters. It employs over 110,000 people, according to the company's website.

Subbotin's brother, Valerie, who also worked in the upper reaches of Lukoil, owns the 184-foot Galvas yacht, and is worth an estimated $100 million, according to SuperYachtFan.

As Newsweek and other outlets noted, Subbotin is one of several Russian business people and members of their families who have died under weird circumstances in the last few months.

At least six have as of late April, Insider has reported, many of whom were linked to large Russian energy companies.

"In all cases, there are widespread suspicions that the deaths may have been staged as suicides, but who did this and why?" Grzegorz Kuczyński, director of the Warsaw Institute's Eurasia Program, told Fortune, Insider noted.

One was Sergey Protosenya, whose wife and daughter were found dead, too.

His son, Fedor, who is still alive, told MailOnline he does not believe local police's theory that it was a murder-suicide, Insider previously wrote.

Lukoil did not immediately respond to a request for comment.