An Austrian newspaper reported on Sunday that Russian President Vladimir Putin was suffering from back problems, and that a Viennese orthopedic expert had traveled to Moscow to treat him.
The Kurier paper did not name the doctor or give the source of the information for its report, which comes amid widespread speculation on the Russian leader's whereabouts.
Putin, who has not been seen in public or on live television broadcasts for more than a week, postponed a meeting with Kazakh and Belarussian leaders last week.
Kremlin spokesman Dmitry Peskov did not pick up his phone when contacted to comment on the report.
A separate report on Sunday by independent news outlet Dozhd said Putin had not been in Moscow for the last several days.
Sources told Dozhd that the president was at his residence on Lake Valdai in Novgorod province. Peskov declined to comment when contacted by Dozhd.
Putin's silence in the past week has fueled feverish speculation on everything from the state of his health to his grip on power and whether he went to Switzerland to watch his girlfriend give birth.
The Kremlin has denied the rumors.
Putin has a scheduled meeting with Kyrgyzstan President Almazbek Atambayev in St. Petersburg on March 16, the Kremlin said in a statement on Friday.