Chechen leader Ramzan Kadyrov has been taken to hospital with suspected coronavirus, Russian media report.
The 43-year-old was flown to Moscow on Wednesday for treatment after developing flu-like symptoms, said Interfax news agency quoting a source.
“He’s in hospital in Moscow,” another source told the Ria Novosti agency.
The authoritarian leader – who previously fought against Moscow as a Chechen nationalist – is now a key ally of Russian President Vladimir Putin.
He has come under scrutiny for imposing his own interpretation of Islamic law in the region, as well as for his poor human rights record.
Unconfirmed reports suggested a plane belonging to Mr Kadyrov was tracked flying from near the Chechen capital, Grozny, to Moscow on Thursday afternoon. His condition is unknown although initial reports suggested his doctor recommended he travel to the Russian capital.
‘In personal control’
A close ally of the Chechen leader, Grozny TV chief Akhmed Dudayev, was quoted by Tass news agency as saying Ramzan Kadyrov “is in personal control of the situation, he takes all necessary measures. The work of his headquarters is under his personal control”.
If confirmed, Mr Kadyrov would be the latest high-profile Russian official to contract the illness.
Prime Minister Mikhail Mishustin only returned to work in the last few days after catching the virus.
President Vladimir Putin’s press secretary Dmitry Peskov also tested positive, as did culture minister Olga Lyubimova and construction minister Vladimir Yakushev – as well as Mr Yakushev’s deputy, Dmitry Volkov.
On Thursday Russia’s reported death toll rose by 127 in the previous 24 hours to 3,099, with confirmed cases jumping to 317,554.
It is the second highest number of recorded infections worldwide. Critics believe the death toll is far higher than officially stated.
The government however says the outbreak is stabilising. The daily rise in new cases has dropped in recent days and on Thursday the number of people discharged from hospital after recovery for the first time exceeded the number of new infections over the previous 24 hours.