The photo was released by Bellingcat to prove that military doctor Alexander Yevgenyevich Mishkin and the suspect in the poisoning of former Russian spy in the UK, Alexander Petrov, are the same person; according to Time.

Bellingcat, an intelligence investigation website, revealed that the suspect Alexander Petrov accused by the UK of poisoning former Russian spy Sergei Skripal and his son is a military doctor with the rank of lieutenant colonel or colonel.

Alexander Yevgenyevich Mishkin, 39 years old, is a military doctor of the Russian Military Intelligence Service (GRU), according to Reuters.

Mishkin's rank in the GRU is unknown. But based on his 15 years of service, Bellingcat speculates he may be a lieutenant colonel or colonel. He was recruited by the GRU while studying at a military medical academy.

Mishkin is believed to have been born in 1979 in Archangelsk in northern Russia and had received formal medical training in the Russian Navy.

Bellingcat added that between 2011 and 2018, Mishkin traveled abroad several times under the name Alexander Petrov, including to Ukraine and the breakaway region of Transdniestria in Moldova.

Bellingcat also said it would release the forensic evidence and other information it used to conclude that Petrov was Mishkin today (October 9). There was no immediate comment from the Russian or British governments on the information Bellingcat released.

British prosecutors accused Mishkin and another man, Ruslan Boshirov, in early September of attempting to assassinate Mr Skripal and his daughter with the nerve agent Novichok in Salisbury in March. However, they said the two suspects used false identities to enter the UK.

Bellingcat on September 26 identified Boshirov’s real name as Anatoliy Chepiga, a GRU intelligence colonel, after finding old photos and a passport of Chepiga with a portrait similar to Boshirov’s. The website’s new investigation shows that Mishkin was born in 1979 in the village of Loyga, Archangelsk district, northern Russia. As of September 2014, his Moscow address was still the GRU headquarters.

"Bellingcat's identification process included multiple open sources, testimony from the subject's acquaintances, as well as copies of personal identification documents, including passports," Bellingcat said.

On the Russian side, in response to the accusation that Boshirov was Chepiga intelligence colonel, Kremlin spokesman Dmitry Peskov said on September 27 that "there are many people who look alike" and refused to confirm the identities of the two suspects. Previously on September 13, Petrov and Boshirov confirmed that they were only in the UK for tourism.

Relations between Russia and the UK remain strained following the incident. The UK and its allies have accused Russia of being behind the assassination and have expelled more than 100 Russian diplomats, while Moscow has flatly denied the allegations and responded by expelling diplomats from 24 Western countries.