Investigative outlet Bellingcat has identified the third suspect in the March 2018 Novichok poisoning of ex-Russian spy Sergei Skripal and his daughter, Yulia, as a high-ranking Russian intelligence officer named Denis Vyacheslavovich Sergeev. Sergeev allegedly traveled to the U.K. days before the Skripals were poisoned under his alter ego Sergey Vyacheslavovich Fedotov. It’s not clear what role, if any, the GRU agent played in the poisoning, and Bellingcat could not confirm that he was in Salisbury at the time. Skripal and his daughter survived the attack—but months later, a woman died after picking up what is widely believed to be a leftover bottle from the poisoning.

The outlet also reports that Sergeev traveled to Bulgaria in 2015, just before a prominent arms trader was allegedly poisoned in that country. Bellingcat further claims that in recent months, Russian authorities have attempted to destroy all records of Sergeev and the other two Skripal suspects. “These unprecedented actions cannot plausibly be taken without direct involvement of the Russian state, and add further credibility to the U.K. government’s assertion that the Skripal poisoning operation, and the subsequent coverup, were coordinated at a state level,” the outlet writes.