The Telegraph reported that Chepiga, 39, had served in wars in Chechnya and Ukraine, and was made a Hero of the Russian Federation by decree of President Vladimir Putin in 2014
The real identity of one of the men wanted by Britain for the Salisbury nerve agent attack on former Russian spy Sergei Skripal and his daughter is Anatoliy Vladimirovich Chepiga, according to media reports on Wednesday which said he was a decorated Russian colonel.
Earlier this month, British prosecutors charged two Russians - Alexander Petrov and Ruslan Boshirov - with attempted murder for the Novichok poisoning of the Skripals in the southern English city in March but said they believed the suspects had been using aliases to enter Britain.
The Daily Telegraph and the BBC said Boshirov's real name was Chepiga, citing investigative reporting by Bellingcat, a website which covers intelligence matters. Two European security sources familiar with the Skripal investigation said the details were accurate.
Russia denies any involvement in the poisoning, and the two men have said they were merely tourists who had flown to London for fun and visited Salisbury to see its cathedral.
The British government knows both their real identities, sources close to the investigation have said.
The Telegraph reported that Chepiga, 39, had served in wars in Chechnya and Ukraine, and was made a Hero of the Russian Federation by decree of President Vladimir Putin in 2014.
The Metropolitan Police, who are investigating the poisoning, and the Foreign Office declined to comment on the report. But British defence minister Gavin Williamson appeared to confirm its veracity on Twitter.
"The true identity of one of the Salisbury suspects has been revealed to be a Russian Colonel. I want to thank all the people who are working so tirelessly on this case," Williamson said in a tweet, which was later deleted without explanation.
Prime Minister Theresa May did not address the reports directly in a speech to the United Nations in New York, but spoke of "the reckless use of chemical weapons on the streets of Britain by agents of the Russian GRU (military intelligence)."
The Russian Embassy in London was not immediately available to comment. The Kremlin has previously said that the suspects have nothing to do with Putin.