In addition, another member of President Putin's inner circle has died. He became the latest member of the Kremlin elite to die under mysterious circumstances.
Vitaly Robertus, vice president of Russian oil giant Lukoil, has died “suddenly” at the age of 54, the company said.
On March 13, Lukoil announced the late executive's death in a short statement in which it expressed its “deepest condolences.”
The cause and circumstances have not been disclosed.
“It is with great regret that we announce the sudden passing of our Vice President Vitaly Robertus at the age of 54,” the company said in a statement.
He is the fourth executive to die since President Vladimir Putin's war against Ukraine began, and the fifth high-profile figure connected to the oil giant.
Mr. Robertus is an incredibly decorated executive who has been with Lukoil for more than 30 years.
“He will remain in our memories as an effective leader, a versatile person and a sympathetic comrade,” the company added.
“The Lukoil team would like to express its deepest condolences to the family and friends of Vitaly Robertus.”
Robertus was also known as one of Russia's most talented aviation modelers.
He is an honorary sports master of the Russian Federation, seven-time Russian champion and four-time world champion in aviation modeling.
He was also a certified airplane and helicopter pilot.
In November, Vladimir Lebedev, a Russian senator and war supporter with close ties to the Kremlin, died suddenly at the age of 60 after suffering a “heart attack.”
No further details were released, but colleagues said he was in good health and called his death a “deep shock.”
Lebedev had a close business relationship with Vladimir Nekrasov, 66, chairman of the board of energy giant Lukoil, who also passed away “suddenly” in November.
Nekrasov was the third top oil company executive to die since the start of the war.
Lukoil initially demanded negotiations to end the fighting with Ukraine, a move that meant to Putin that the company was not loyal to him.
In September 2022, before Lebedev and Nekrasov died, Lukoil businessman Rabil Maganov, 67, fell from a window at Moscow's elite Central Clinical Hospital, also known as the Kremlin Clinic.
Murder was suspected, but Maganov, who had been hospitalized with a long-standing heart condition, fell from a sixth-floor window and died on the spot.
That same morning, President Putin rushed into the hospital to pay his final respects to Mikhail Gorbachev, the last leader of the Soviet Union, who died the same week.
Billionaire Alexander Sabotin, 43, who also had ties to energy giant Lukoil, where he was a top manager, was found dead in May 2022.
One theory circulating is that Sabotin was poisoned by a toad, causing a heart attack.
Several Russian generals have been killed since the war began, as have all Lukoil executives.
Colonel Gennady Zikko, 58, was found dead of a mysterious illness after being expelled from military headquarters in August.
Redovka, a news site loyal to Putin's government, reported that Zydko died after a “long illness.”
His death was also confirmed by Mikhail Degtyarev, the governor of the Khabarovsk region, another Kremlin supporter.
However, there has been no official announcement yet, and neither report mentions where he died.
Meanwhile, General Vladimir Sviridov (68) and his wife Tatiana (72) were found in their home in the village of Azhievsky, Stavropol region.
The former commander-in-chief of Russia's air defense chief once criticized President Vlad for allowing a “third-rate” air force.
He called on President Putin to “create normal living conditions for all military personnel, not just young officers, so that they can properly carry out their duties.”
Authorities have not yet confirmed the cause of their sudden deaths.