LONDON (Reuters) - British defense minister Gavin Williamson said the “true identity” of one of the suspects in a nerve agent attack on a former Russian spy in Salisbury had been revealed, apparently confirming media reports that the suspect was a 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. Russia denies involvement.

Boshirov’s real name is Anatoliy Vladimirovich Chepiga, according to two European security sources familiar with the Skripal investigation, who confirmed media reports that cited investigative reporting by website Bellingcat.

“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.