The Federal Space Agency said Sunday that its chief, Vladimir Popovkin, has been hospitalized.
Agency spokesman Alexei Kuznetsov confirmed the hospitalization but would not elaborate.
National news agencies earlier quoted the space agency's press office as saying Popovkin had been taken to the hospital with "physical and emotional exhaustion."
Popovkin, 54, has been leading the space agency since April.
The tabloid Lifenews.ru on Sunday posted a photo of Popovkin with his head bandaged, and quoted sources as saying the space chief had been drunk when taken to the hospital.