SEVERAL DOCTORS HAVE been prevented from seeing Russian opposition leader Alexei Navalny in a prison hospital after his three-week hunger strike.

Navalny was transferred on Sunday from a penal colony east of Moscow to a prison hospital in Vladimir, a city 180 kilometres east of the capital, after his lawyers and associates said his condition had dramatically worsened.

Reports about Navalny’s rapidly deteriorating health have drawn international outrage.

His personal doctor, Dr Anastasia Vasilyeva, led three other medical experts to try to visit Navalny at the prison clinic and the IK-3 prison in the city of Vladimir.

They were denied entry after waiting for hours outside the gates.

Navalny, who is Russian President Vladimir Putin’s most adamant opponent, has been on a hunger strike since 31 March to protest over the prison officials’ refusal to let his doctors visit him and provide adequate treatment for his back pains and numbness in his legs.

Russia’s penitentiary service insists that Navalny was getting all the medical help he needs.

The prison service said in a statement yesterday that Navalny’s condition was deemed “satisfactory”.

But another of his doctors, Dr Yaroslav Ashikhmin, said over the weekend that test results provided by his family show Navalny has sharply elevated levels of potassium, which can bring on cardiac arrest, as well as heightened creatinine levels that indicate impaired kidney function.

Navalny was arrested in January upon his return from Germany, where he had spent five months convalescing from a nerve agent poisoning he blames on the Kremlin – an accusation Russian officials have rejected.

His arrest triggered the biggest protests seen across Russia in recent years.

In February, a Moscow court ordered him to serve two-and-a-half years in prison on a 2014 embezzlement conviction that the European Court of Human Rights deemed to be “arbitrary and manifestly unreasonable”.

In response to Navalny’s deteriorating health, his associates have called for a nationwide rally tomorrow, the same day that Putin is scheduled to deliver his annual state of the nation address.

Russian authorities, meanwhile, have escalated their crackdown on Navalny’s allies and supporters, with the Moscow prosecutor’s office asking a court to brand Navalny’s Foundation for Fighting Corruption and his network of regional offices as extremist organisations.

Human rights activists say such a move would paralyse their activities and expose their members and donors to prison sentences of up to 10 years.