MOSCOW — Russia’s most prominent opposition figure, Alexei Navalny, raised questions Monday about whether he had been poisoned in prison after being convicted of calling for a protest that led to one of the largest street demonstrations in Moscow in years.
Navalny, 43, was sent from the government hospital where he was being treated for an unknown illness back to prison earlier in the day. His return to jail came over the strenuous objections of his doctor, who said the cause of his symptoms had not been identified, but he had apparently been poisoned with a “toxic agent.”
The opposition leader posted a message on his official website that addressed the possibility that authorities had poisoned him.
Navalny wrote that on the one hand, why would authorities poison him while in custody, as they would be the obvious culprits? On the other hand, he noted, this had never stopped them before.
“Are they such idiots as to poison me in a spot where they would be they only suspects?” he wrote, before listing a string of incidents involving opposition figures and others where the government was clearly to blame. “The dudes in power in Russia are truly rather moronic and asinine,” he wrote.
His doctor, Anastasy Vasilyeva, said insufficient tests had been conducted on the cause of Navalny’s condition to allow him to return him to the place where she said the toxic exposure probably occurred. After being allowed to see him, Vasilyeva wrote on Facebook that Navalny was feeling better but needed continued monitoring.
Navalny, the most high-profile critic of President Vladimir Putin and his government, was rushed to the hospital Sunday from his jail cell, suffering from swelling and hives, which officials described as an allergic reaction. He was sentenced last week to 30 days in jail for organizing an illegal protest, days before a demonstration he had called drew thousands of people in Moscow on Saturday.
Vasilyeva said Sunday that Navalny might have been poisoned with an unknown chemical substance. The Interfax news agency quoted a doctor at the government hospital where he was admitted as saying that he had suffered from an attack of hives but had improved.
In describing the events around his hospitalization, Navalny said on his website that his cellmates noticed on Saturday that the skin on his neck was reddening, and as the day progressed his face, ears, and neck began burning and prickling. He could not sleep, and by Sunday morning his head was severely swollen, his eyes were just slivers, and his eyelids were the size of “Ping-Pong balls.”
Navalny said he had never experienced allergies to food or to pollen, although he had previously had an occasional skin reaction to toiletries, but not of the kind in the cell. He said he had been in the exact same bunk for 10 days just a few weeks ago, and after nine or 10 times in jail, he always brought his own sheets, soap, and toothpaste.
The opposition leader said he started to improve after a doctor gave him a shot, but he was not told anything about his condition and only discovered some details from a hospital report given to a news agency.
Unease among his fellow opposition members and supporters stemmed from the Kremlin’s long history of eliminating its opponents, often by poisoning them.
Putin has tried to build an image of a powerful, united Russia, and anyone who would undermine that strength or point out that much of the country lives in poverty is often the target of official ire.
Independent journalists, rights advocates, opposition politicians, government whistleblowers, and others are smeared in the media, jailed on dubious charges and, in some cases, killed. Navalny himself temporarily lost most of the vision in one eye when someone threw a caustic liquid into his face in 2017.
Sergei Skripal, a former Russian spy, was poisoned along with his daughter in Salisbury, England, last year with a potent nerve agent administered by two officers from Russia’s military intelligence, Britain said. Russia has denied any involvement even though surveillance cameras caught the officers wandering around Salisbury.
Vladimir Kara-Murza, another opposition leader, has accused the government of poisoning him twice, sending him into a coma in the latest attempt in 2017, although medical tests conducted abroad proved inconclusive.
Alexander V. Litvinenko, a former officer in the Russian security service FSB who became a Putin opponent, died of polonium-210 poisoning in London in 2006.
Boris Nemtsov, a prominent opposition politician, was fatally shot outside the Kremlin in February 2015. Although several people from Chechnya were convicted in the killing, neither the mastermind nor a motive was ever identified.
Sergei L. Magnitsky, a lawyer and auditor, was jailed on tax evasion charges while investigating a $230 million government tax “refund” that corrupt Russian officials had granted to themselves. Denied essential medical care, he died in 2009.
Journalist Anna Politkovskaya, a critic of Putin who wrote of atrocities by the Russian military in Chechnya, was shot to death in her Moscow apartment in 2006.
And in a case dating back even further, Yuri Shchekochikhin, a Russian journalist and politician famous for his corruption exposés, fell ill and died suddenly in 2003. His death was attributed to a rare allergic reaction, but the case was never fully resolved publicly.
Analysts have described both Navalny’s medical emergency and the mass detentions Saturday, when police carted away almost 1,400 protesters, as possible signs of the Kremlin’s unease about Putin’s continued drop in the polls, with Russians grumbling about their stagnant incomes. They said that instead of doing the hard work of changing policies to woo those who are angry with Kremlin, the government is trying to silence them.
The immediate cause of the Moscow protests was anger over the Moscow City Electoral Commission’s preventing opposition candidates from registering for the September election for the 45-member city council. Fifty-seven potential candidates were blocked, including about 17 government critics.
“There are thousands of Muscovites behind every opposition member that was not allowed to run,” Nikolai Petrov, a Russian political science professor at the Higher School of Economics in Moscow, wrote in the Vedomosti daily. “Today these are the people, and not just 17 unregistered candidates, who are in the position of being very harsh critics of the government.”
Hence the crackdown will feed more protests, he said, adding that “it is hard to imagine what they will do next, but it won’t be pleasant for the government.”
The next Moscow protest is scheduled for Saturday.