Three members of Ukraine's negotiating team were poisoned while attending peace negotiations with their Russian counterparts but survived the ordeal, the Wall Street Journal reported on Monday,

The open-source investigation outlet Bellingcat, which has uncovered numerous Russian intelligence plots including the poisonings of opposition leader Alexey Navalny and former spy Sergei Skripal, confirmed the reporting.

Among those poisoned was Roman Abramovich, a Russian oligarch who has been tapped as an informal intermediary between Russia and Ukraine. Abramovich, whose late mother was born in Ukraine, had come under sanctions from the United Kingdom and European Union for his relationship with the Kremlin and President Vladimir Putin. The U.S. has not sanctioned the oligarch, reportedly at the request of Ukraine’s President Volodomyr Zelensky because of his role in peace talks.

According to Bellingcat, the suspected poisoning took place on March 3 and 4, a week after the war began on Feb. 24. At a meeting on Ukrainian territory with the Russian delegation, the two sides attempted to seek room for negotiation that would bring the fighting to an end, but it appears this meeting was where the three were targeted.

The victims reportedly began to suffer from symptoms including eye and skin inflammation and piercing pain in the eyes that did not disappear until the following morning when they were due to travel to Istanbul. The three men reportedly only consumed chocolates and water on the night of the incident.

After the poisoning attempt, Bellingcat said that it dispatched an investigator to assist with the examination of the suspected poisoning. Together with chemical weapons specialists, it determined that the team was the victim of an "intentional poisoning" with an "unidentified chemical weapon."

Abramovich confirmed through his spokesperson that he had indeed been poisoned but was now healthy. Rustem Umerov, a member of the Ukrainian negotiating team who suffered symptoms, also confirmed that he is “fine”, but cautioned against following false reports.

“Please do not trust any unverified information. We have an informational war ongoing as well,” wrote Umerov on Twitter, without directly referring to the poisoning.

Fears that Russia may resort to chemical weapons or other weapons of mass destruction have been heightened in recent weeks. The NATO alliance and the U.S. itself have warned Russia against any use of chemical or biologicial weapons against Ukraine.

"We would respond if he uses it," President Joe Biden said at a news conference on March 25. "The nature of the response would depend on the nature of the use."