A third suspect linked to the Salisbury poisoning has been named by an investigative website as Denis Sergeev, a high-ranking Russian military intelligence officer.

Bellingcat said Mr Sergeev, 45, is a senior member of Russia's GRU agency who uses the alias Sergey Fedatov.

Sky News has independently verified that the name is correct and Sergeev is thought to be a senior member of Russia's GRU.

The alias Fedatov has been identified previously by Bellingcat, which also exposed the true identifies of the other two Russian intelligence officers who are suspected by Britain of the attempted murder of Sergei Skripal, a Russian double agent, and his daughter last March.

Their names are Colonel Alexander Mishkin and Colonel Anatoliy Chepiga. Both men deny any involvement in the novichok attack, claiming to have been in Salisbury on the day the Skripals fell critically ill because they were tourists.


Image: The other two suspects are Colonel Anatoliy Chepiga (l) and Colonel Alexander Mishkin

The British authorities have not confirmed there is a third suspect but their investigation into the attack is ongoing.

The website claimed that in the last two months, Russian authorities "have taken the unusual measure of erasing any public records of the existence of Denis Sergeev, as well as of Anatoly Chepiga and Alexander Mishkin",

It said: "These unprecedented actions cannot plausibly be taken without direct involvement of the Russian state, and add further credibility to the UK government's assertion that the Skripal poisoning operation, and the subsequent cover-up, were coordinated at a state level."

Image: Sergeev is believed to be a high-ranking Russian military intelligence officer

Bellingcat, working with two investigative partners, said it has accessed the flight records of Mr Sergeev, which showed he was in the UK at the time of the attack.

He allegedly flew back to Moscow on the day it happened - 4 March 2018 - via Rome instead of taking a flight that he had been booked on with the other two suspects from London.

The investigative website also claimed he had been in Bulgaria in 2015 just before a Bulgarian defence industry businessman and his son fell ill in a suspected poisoning.

Bellingcat said it had gathered the information over a four-month period working with The Insider (Russia) and Czech publication Respekt. A Finnish newspaper called Helsingin Sanomat also contributed to the research.

Image: Sergei and Yulia Skripal were attacked with novichok and found slumped on a bench in Salisbury in March 2018

Tracing the suspected Russian officer's life story, the analysis claimed Mr Sergeev, who is said to be married with an adult daughter, originally served in the army or the navy, potentially in the special forces.

He transferred to an elite military diplomatic academy known as the "GRU Conservatory" at some point between 2000 and 2002. The GRU is the acronym given to the Russian military intelligence service.

The academy produces around 100 elite intelligence officers a year.

"We have not established what Denis Sergeev's service prior to the academy involved; however, it is known that recruitment into the Academy takes place among military officers with the minimum rank of captain who have excelled at their military service, traditionally in Spetsnaz [Russian special forces] or navy units," the Bellingcat investigation said.

"Like all other graduates, Sergeev would have finished the academy with a minimum rank of lieutenant-colonel. While we have no confirmation of his current military rank, the time served and the nature of his assignments since graduation indicate he currently holds a minimum rank of full colonel, and possibly major-general."

Tracking the roots of Sergeev's alias Sergey Fedotov, the investigation said the alter ego was created in 2010 when a new, valid passport was issued under this name, by the same "770001" passport desk in Moscow that issued cover passports to the other two Skripal suspects, Mishkin and Chepiga.

Novichok suspects: 'We were just tourists'

Bellingcat said "Fedotov" was given a birth date matching the one of the actual person Denis Sergeev.

Tracking a number of data bases, the website said it had followed the travel movements of the man posing as Fedotov between 2012-2018.

During 2016, he travelled to London twice - before and after the Brexit referendum, the website said.

He returned to London on 2 March 2018 - two days before the Skripal poisoning, leaving Moscow at 7:00 on Aeroflot flight SU 2580.

"The other two suspects, Mishkin and Chepiga, would arrive on a later flight that afternoon."

The website said: "It is unclear what Fedotov's role may have been, if any, in the preparation and execution of the poisoning operation.

"We could also not established if he travelled to Salisbury on any of the days he was in the UK."

Image: Experts in protective suits at the site where the Skripals were found

The flight records indicate he was booked on a flight back to Moscow at about noon on March 4 - the day of the poisoning - but never showed up to that flight and instead flew back to Russia the same day from Rome.

Between 2004 and 2012, the investigative website claimed that Sergeev, using his real name, was a shareholder or managing director of eight Russian companies.

"These companies, all of which were liquidated between 2007 and 2012, were sham corporations with names mimicking names of other large companies registered in Russia," it said.

"In most of the companies, Sergeev was the sole shareholder, while in two he was co-shareholder with other people, some of whom we also identified as GRU officers."

The analysis continued: "We established that during 2009, Denis Sergeev obtained a personal loan from a Russian bank in the amount of just over one million USD. The allocation of such a large loan to a person who - as seen from his credit record (obtained from a leaked Russian credit history collection) - had no real estate and no personal vehicle - is extraordinary.

"The loan appears to have been extended on the strength of Denis Sergeev's personal income in his declared role as "specialist" working for a company called Loreven Style Ltd specialising in consulting services."