In response to early reports yesterday, the maestro's Moscow spokesperson, Natalia Dollezhal, had told the Associated Press that she had no knowledge of any hospitalization, saying, "I saw him three days ago. He was in a sanatorium near Moscow. It's not a hospital. It's for rehabilitation." (She added that she hadn't been in touch with him since because she had the flu and didn't want to pass it on to him.)

However, an unnamed family friend told the RIA-Novosti news agency today that Rostropovich is in a hospital in Moscow itself. Dollezhal subsequently told Agence France-Presse that "He has been hospitalized for a routine procedure for three days," adding that this procedure had no bearing on his condition more generally. She would not elaborate.

Rostropovich has been in precarious health for several months. Last fall he cancelled a planned series of Shostakovich centennial concerts with the National Symphony Orchestra in Washington (of which he is Conductor Laureate) when his doctors forbade him to travel across the Atlantic. Over the New Year's holiday, according to the Moscow newspaper Komsomolskaya Pravda, the maestro spent a week in Moscow's Central Hospital for what was reported as an aggravated ulcer.

While in Paris in early February, he fell ill and was rushed to a hospital, but promptly checked himself out and returned to Moscow, where he was hospitalized for a month. While Dollezhal maintained that his condition were not serious, Komsomolskaya Pravda and other newspapers wrote that he was in the Blokhin Center, Russia's leading cancer clinic, where he underwent a "very complicated operation" on his liver, reportedly to remove a tumor.

In early March, Rostropovich was transferred from the hospital to a sanatorium in a resort area outside Moscow. (At that point Dollezhal did confirm that he had undergone a complex liver operation, though she would not discuss where he had been hospitalized or the nature of his ailment.) He did appear at the Kremlin on his 80th birthday, March 27, for a gala celebration hosted by President Vladimir Putin, though by all accounts he appeared pale and weak.

Last week Komsomolskaya Pravda reported that Rostropovich's doctors in Moscow, who regularly traveled out to the sanatorium to check on him, decided just around the time of his birthday that he should return to the clinic after his daughter told them that that his condition had worsened.

A source close to the maestro told the paper that Rostropovich had not happy at the sanatorium — he would sometimes grumble, "What, are you keeping me here like I'm in prison?" — but that he felt no better there than he had at the hospital.