MOSCOW, March 29 (France24) - Russian billionaire Roman Abramovich and Ukrainian peace negotiators suffered symptoms of suspected poisoning earlier this month after a meeting in Kyiv, the Wall Street Journal and the investigative outlet Bellingcat reported on Monday, citing people familiar with the matter.

Abramovich, who accepted a Ukrainian request to help negotiate an end to the Russia invasion of Ukraine, and at least two senior members of the Ukrainian team, were affected, the WSJ report said.

Ukrainian officials poured cold water on the report. Asked about the suspected poisoning, Ukrainian negotiator Mykhailo Podolyak said "there is a lot of speculation, various conspiracy theories". Rustem Umerov, another member of the negotiating team, urged people not to trust "unverified information".

Ukrainian Foreign Minister Dmytro Kuleba later took a similar line, saying in an interview on national television that "everyone is thirsty for news and sensations". However, he also added wryly: "I advise anyone going for negotiations with Russia not to eat or drink anything, (and) preferably avoid touching surfaces".

A U.S. official said intelligence suggested an "environmental" reason for the sickening of Abramovich and the negotiators, "E.g., not poisoning". The official spoke on condition of anonymity and did not elaborate further.

The Kremlin did not immediately respond to an emailed request for comment.