Alexei Navalny
Alexei NavalnyReuters

Russian opposition leader Alexei Navalny has been moved to a medical facility to be treated for a possible respiratory illness and has been tested for COVID-19, The Independent reported on Monday, citing a Russian newspaper.

Navalny had said earlier that he had a high temperature and bad cough.

The 44-year-old said three of the 15 inmates in his Russian prison ward were being treated in hospital for tuberculosis and joked that catching the disease might offer him relief from his other ailments.

"If I have tuberculosis, then maybe it'll chase out the pain in my back and numbness in my legs. That'd be nice," he wrote on Instagram.

The Russian Izvestia newspaper later carried a statement from the state penitentiary service saying Navalny was moved to the prison colony’s sanity unit after a checkup found he had "signs of a respiratory illness, including a high fever”.

Navalny, one of Russian President Vladimir Putin's most prominent critics, was arrested on January 17 for alleged parole violations after returning from Germany, where he had been recovering from being poisoned with a military-grade nerve agent.

He was later sentenced by a Russian court to a three-and-a-half-year sentence, though his lawyer said he would serve only two years and eight months in jail because of time he has already spent under house arrest.

Members of Navalny’s team say he had lost a substantial amount of weight even before he launched a hunger strike on Wednesday to protest the authorities’ failure to provide proper treatment for his back and leg pains.

Amnesty International's secretary general, Agnes Callamard, said she had appealed to Putin over Navalny's "arbitrary arrest and deteriorating health condition".

"There is a real prospect that #Russia is subjecting him to a slow death. He must be granted immediate access to a medical doctor he trusts and he must be freed," she tweeted, according to The Independent.