According to widespread reports, one of the men suspected of murdering former Russian spy Alexander Litvinenko in London has died of Covid-19 in Moscow.

Dmitri Kovtun was one of two persons who, according to a 2006 British investigation, poisoned Mr. Litvinenko's tea with rare radioactive material.

According to allegations ascribed to Tass's Russian news outlet, Mr. Kovtun caught coronavirus before passing away in a Moscow hospital.

Mr. Kovtun and Mr. Lugovoi were accused of being responsible for the murder of Mr. Litvinenko at the Millennium Hotel in Mayfair sixteen years ago.

According to Tass, Mr. Lugovoi, a current member of the Russian parliament, lamented the passing of a "close and loyal friend."

A British public inquiry found in 2016 that the assassination of the vocal critic of Vladimir Putin, who died after ingesting radioactive polonium-210-laced tea, was "probably" authorized by the Russian president.

The investigation, led by the retired High Court judge Robert Owen, concluded that Mr. Lugovoi and Mr. Kovtun intentionally poisoned Mr. Litvinenko by inserting a radioactive chemical in his drink at a key London hotel causing his agonizing death.

The European Court of Human Rights (ECHR) also concluded that Russia was guilty of his death following a complaint made by the deceased's widow, Marina Litvinenko.

Russia has long denied any participation in the death and resisted international arrest requests issued for Mr. Kovtun and Mr. Lugovoi.

Owen's Litvinenko investigation concluded that the use of the radioactive substance, which could only have come from a nuclear reactor, was a "strong indicator" of state involvement and that the two men had likely been acting under the direction of Mr. Litvinenko's former employer, the FSB, and the KGB.

Possible motives included Mr. Litvinenko's work for British intelligence agencies after he fled Russia, his criticism of the FSB, and his association with other Russian dissidents; it was also suggested that there was a "personal dimension" to the animosity between Mr. Litvinenko and Mr. Putin.