Dmitry Kovtun, a former Russian intelligence agent accused of fatally poisoning a fellow ex-spy with green tea laced with radioactive polonium in the bar of a luxury London hotel, died on Saturday in a hospital in Moscow. He was 56.
The cause was complications of Covid-19, said Andrei Lugovoi, a childhood friend of Mr. Kovtun’s who is accused of being his accomplice in the murder.
Mr. Kovtun and Mr. Lugovoi had met their fellow K.G.B. spy, Alexander V. Litvinenko, at the toffee-toned Pine Bar of the Millennium Hotel on Nov. 1, 2006, to discuss potential investments by British companies in Russia. Three weeks later, Mr. Litvinenko died in a London hospital.
Mr. Litvinenko had been fired from the Russian Federal Security Service for publicly linking the spy agency to organized crime and for saying that he had been ordered to assassinate Boris Berezovsky, an exiled Russian oligarch and arch-critic of President Vladimir V. Putin. After being jailed for abuse of office and later acquitted, he sought asylum in Britain in 2000.
In a book published in 2003, Mr. Litvinenko also accused the Russian intelligence agency of complicity in apartment bombings in Moscow in 1999 for which the agency had blamed Islamist separatists from Chechnya.
On his deathbed, the 43-year-old Mr. Litvinenko accused Mr. Putin of his assassination, which his son said was caused by “a little, tiny nuclear bomb,” prompting a radiation alert in London.
“You have shown yourself to be as barbaric and ruthless as your most hostile critics claim,” Mr. Litvinenko said in a written statement shortly before he died. “You may succeed in silencing one man. But a howl of protest from around the world will reverberate, Mr. Putin, in your ears for the rest of your life.”
Traces of polonium were found in the Pine Bar, and in hotel rooms and other locations that Mr. Kovtun and Mr. Lugovoi had occupied.
Weaponizing polonium 210, which is used to produce antistatic materials, would not have been beyond the imagination of the Kremlin’s version of Q, the research and development genius of the James Bond novels and films.
In 1978, Georgi Markov, a Bulgarian dissident, was said to have been jabbed with a poison-tipped umbrella in London with the connivance of the K.G.B. The Federal Security Service, the K.G.B.’s successor, was implicated in subsequent poisonings of Mr. Putin’s critics.
Mr. Litvinenko was investigating the death of Anna Politkovskaya, a Russian journalist who was shot to death in her Moscow apartment building the month before he died.
In 2016, after a protracted demand for answers from Mr. Litvinenko’s widow, Judge Robert Owen, who had since retired from the British High Court, delivered an unequivocal finding: “I am sure that Mr. Lugovoy and Mr. Kovtun placed the polonium 210 in the teapot at the Pine Bar on 1 November 2006. I am sure that they did this with the intention of poisoning Mr. Litvinenko.”
Judge Owen also concluded that the evidence “establishes a strong circumstantial case that the Russian State was responsible for Mr. Litvinenko’s death,” and that the security service’s operation was “probably approved” by Mr. Putin.
Last year, the European Court of Human Rights ruled that Russia was responsible for the killing.
Dmitry Vladimirovich Kovtun was born into a military family on Sept. 25, 1965, in Moscow. In the 1980s, he attended the Moscow Higher Military Command School, where his classmates included Mr. Lugovoi. After they graduated, they served in the K.G.B.’s ninth directorate, which was responsible for protecting the Kremlin’s top brass.
While Mr. Lugovoi became a public figure as a member of the Russian Parliament, much less is known about Mr. Kovtun’s career path after the Soviet Union collapsed.
He and his German-born wife, Inna Hohne, moved to Hamburg, where he later claimed political asylum. The couple separated, and he returned to Moscow as a business consultant after he had worked as a waiter and, Ms. Hohne was quoted as saying, aspired to act in pornographic movies.
Information about survivors was not immediately available.
According to Judge Owen’s report, Mr. Lugovoi and Mr. Kovtun also tried to poison Mr. Litvinenko at an earlier meeting in London, in October 2006.
The police found traces of radiation not only in Mr. Kovtun’s London hotel room but also on a couch in his former wife’s apartment in Hamburg, where he had slept before leaving for Britain, as well as in his mother-in-law’s house — but not in his own apartment in Germany.
Both men denied any complicity in Mr. Litvinenko’s death. Russia refused to extradite them.
In early December 2006, Mr. Kovtun was himself hospitalized in Moscow for radiation poisoning. He told Russia’s Channel One TV, “It is that I brought it back from London where I met Alexander Litvinenko.”
But Judge Owen dismissed accounts by the accused poisoners that Mr. Litvinenko had ordered the tea in the Pine Bar himself. (“We did not pour anything for him,” Mr. Kovtun said.)
The judge also disputed Mr. Kovtun’s claim that he was too focused on his cigar or too drunk on his way to a football match to recall any details of their conversation a few weeks after the fact, even though eight years later he was able to describe how Mr. Litvinenko had “grabbed the teapot on the table and, without waiting for an invitation, poured himself some tea” and had “gulped down two cups of hot tea one after the other.”
“There is no reason at all to think that Mr. Kovtun’s memory had improved dramatically so many years after the event,” Judge Owen’s 2016 report declared. “The only logical conclusion is that he was lying on one or other (or both) of the two occasions.”