The artistic director of the Bolshoi Theatre's ballet troupe may lose his sight after he was attacked with acid in Moscow, the theatre said.
Sergei Filin, a 42-year-old former ballet star, was approached by an unknown man who splashed acid on his face as he got out of his car outside his home in central Moscow on Thursday night, Russian television reported.
Bolshoi spokeswoman Katerina Novikova, who visited Mr Filin in hospital, told the Associated Press that his condition is stable but his eyesight is at risk.
Mr Filin was appointed artistic director of the Bolshoi's ballet company in March 2011. He danced for the Bolshoi on and off from 1988 to 2004 when he suffered a severe injury on stage.
The theatre's director-general, Anatoly Iksanov, told Russia's Channel One that he believes the attack is linked to Mr Filin's work.
"He was a man of principle and never compromised," Mr Iksanov said. "If he believed that this or that dancer was not ready or was unable perform this or that part, he would turn them down."
Several stars at the Bolshoi including Nikolai Tsiskaridze, one of its most celebrated dancers, have complained about what they call Mr Filin's unfair treatment of dancers at the Bolshoi.