Photo: The Canadian Press

Russian opposition leader Alexei Navalny, who is in the third week of a hunger strike, will be admitted to a hospital in another prison, the Russian state penitentiary service said Monday, after the politician's doctor said he could be near death.

The prison service, FSIN, also said that Navalny had agreed to take vitamin therapy, but an ally of the 44-year-old Kremlin critic cast doubt on that and the hospital transfer, saying his lawyers should confirm both.

The service said in a statement that Navalny would be transferred to a hospital for convicts located in a penal colony in Vladimir, 180 kilometres east of Moscow. According to the statement, Navalny’s condition is deemed “satisfactory.”

But the opposition leader's physician, Dr. Yaroslav Ashikhmin, said Saturday that test results he received from the family show him with sharply elevated levels of potassium, which can bring on cardiac arrest, and heightened creatinine levels that indicate impaired kidneys.

“Our patient could die at any moment,” he said in a Facebook post.

Navalny, President Vladimir Putin’s fiercest opponent, was arrested in January upon his return from Germany, where he had spent five months recovering from a nerve agent poisoning he blames on the Kremlin — accusations Russian officials have rejected. Navalny’s arrest triggered a massive wave of protests all across Russia, the biggest show of defiance in recent years. Soon after, a court ordered Navalny to serve 2 1/2 years in prison on a 2014 embezzlement conviction that the European Court of Human Rights deemed to be “arbitrary and manifestly unreasonable.”

Navalny went on hunger strike in prison to protest the refusal to let his doctors visit when he began experiencing severe back pain and a loss of feeling in his legs. Russia’s state penitentiary service has said that Navalny was receiving all the medical help he needs.

In response to the alarming news about Navalny’s health this weekend, his team has called for a nationwide rally on Wednesday, the same day that Putin is scheduled to deliver his annual state of the nation address.