A former top manager at Russian gas giant Novatek, Sergei Protosenya, his wife, and his daughter have been found dead in a rented villa in Spain, local media reported on April 21.
The 55-year-old millionaire was found hanged, while his wife and daughter had been stabbed to death in a villa in the town of Lloret de Mar near Barcelona on April 19, police were quoted as saying.
Police are said to be looking into two possible scenarios -- that Protosenya killed his wife and daughter and then hanged himself, or that someone killed the entire family and then staged the crime scene, the Spanish news site Telecino reported.
Protosenya, a former chief accountant of Novatek, used to be a member of the energy company's board of directors. His wealth was estimated at around 400 million euros ($433 million).
He and his family resided mainly in France.
Novatek is Russia's largest independent natural-gas producer and analysts say its phenomenal rise from a bit player in the early 2000s to a $79 billion company in September* -- not far behind BP's $89 billion market value at the time -- was due in large part to the company's connections to the Kremlin.
Gennady Timchenko, a key Novatek shareholder, is considered a close associate of Russian President Vladimir Putin. Their friendship goes back to the early 1990s.
The market value of Novatek has cratered since Western governments imposed sanctions on Russia for its invasion of Ukraine.
SEE ALSO: Executive Of Russian Gas Company Arrested In U.S. Says He Will 'Vigorously' Fight ChargesLate last year, a top official at Novatek was arrested in the United States on tax charges. Mark Gyetvay, the deputy chairman of Novatek's management board, said at the time that he was innocent and would "vigorously" fight the case.
The U.S. Justice Department said on September 23 that Gyetvay had been arrested on tax charges related to $93 million hidden in offshore accounts and faced up to 20 years in prison if convicted.
*CLARIFICATION: A previous version of this article failed to note the collapse in Novatek's market value since the imposition of sanctions following Russia's invasion of Ukraine.