The chairman of Russian energy giant Lukoil, Ravil Maganov, died on Thursday, the Moscow police said.
Maganov fell out of a window of a clinical hospital, where he was being treated for an illness, and died of injuries, according to the police.
"The incident occurred at about 7 a.m. Moscow time (0400GMT) in the Central Clinical Hospital on Marshal Tymoshenko Street. A man fell out of the window of the sixth floor, he died of his injuries," the police statement said.
Maganov was 67.
Lukoil is one of the largest Russian oil companies and the second in terms of oil production in Russia.