Chechnya's leader Ramzan Kadyrov was flown to a Moscow hospital on Thursday with a suspected Covid-19 infection, Russian news agencies reported.
"Ramzan Kadyrov was taken by plane to Moscow with a suspected case of coronavirus. Now he is under medical supervision," a medical source told state news agency Tass.
The source said Mr Kadyrov was in a stable condition.
He is the latest senior official to contract the virus after Russian Prime Minister Mikhail Mishustin, Kremlin spokesman Dmitry Peskov and several ministers.
There was no immediate comment from officials in Chechnya or Moscow.
An aide to Mr Kadyrov, Grozny TV chief Akhmed Dudayev, said the Chechen leader was "in personal control of the work of the coronavirus headquarters", RIA Novosti reported.
The report did not mention that he was admitted to hospital.
A crucial ally of Russian President Vladimir Putin, Mr Kadyrov took power in Chechnya after his father, Akhmat Kadyrov, was killed in a 2004 bomb attack.
Both father and son fought against Moscow during the first separatist conflict in Chechnya, from 1994 to 1996.
But they switched sides to support the Kremlin in a second war in 1999.
Russia has recorded 317,554 coronavirus infections, the second-highest in the world after the US, with 3,099 deaths nationwide.
Despite the high number of infections, officials say the situation is stabilising and the mortality rate is low.
They have begun to ease lockdown measures in many parts of the country.