The controversial cyber-sleuths claimed on Wednesday that one of the men named by the United Kingdom as a suspect in the "chemical attack" on former Russian double agent Sergei Skripal and his daughter Yulia in Salisbury this March is actually a colonel in Russian special forces.
British Prime Minister Theresa May has said that the men suspected of the poisoning were members of Russian military intelligence acting on orders from a "high level".
The new report says Chepiga is a highly-decorated GRU officer with the rank of colonel, who assumed the identify of Ruslan Boshirov for his undercover mission in Britain.
Mrs May said Russian Federation had "sought to obfuscate through desperate fabrication".
Bellingcat said it believed that "Boshirov" was in fact Chepiga after obtaining documents relating to his passport.
Two Russian men later appeared on the state-funded RT channel and made widely mocked claims that they only went to England in early March to visit the "wonderful town" of Salisbury and its famous cathedral.
Bellingcat said it had received tips from former Russian military officers and perused pictures of graduates of Russian military academies.
The journalists said they identified Chepiga first by looking into elite military academies in Russia's far east, where they had been tipped off he might have studied.
He and the other suspect in the case, now still known as Alexander Petrov, were captured on CCTV in Salisbury on the day before and the day of the poisoning of the Skripals in March.
Chepiga, according to Bellingcat, was born on May 5, 1979, in the village of Nikolaevka, in the Amur region close to Russia's border with China.
The pair claimed they have been left fearing for their lives after Britain pointed to their involvement and said they were officers in Russian military intelligence service the GRU. Other Russian soldiers who have recently received the award with few details mentioned have been found to be fighting covertly in eastern Ukraine or Syria.
They denied the British claim that they were Russian military intelligence officers, saying they worked in the nutritional supplements business. The group eventually tracked down Chepiga's passport file, dated 2003, with a picture bearing a strong resemblance to Boshirov.
The pair maintain they were holidaying in Salisbury and had nothing to do with the attack in March. Sergei Skripal's daughter Yulia Skripal seen in this undated photo.
In a translation from Russian, the pair told RT editor-in-chief Margarita Simonyan they worked in the fitness industry.
Bellingcat's latest revelation came after scouring the records of specialist military schools that would provide the training necessary for the covert work the two suspects engaged in.