Russian Oligarch Roman Abramovich and Ukrainian peace negotiators were the victims of a suspected poisoning earlier in March, reports say.
The sanctioned Russian billionaire and at least two senior members of the Ukrainian team were affected after a meeting in Kyiv, according to the Wall Street Journal and the investigative site Bellingcat.
The WSJ report said their symptoms included red eyes, constant and painful tearing, and peeling skin on their faces and hands. But their conditions have since improved and their lives are not in danger.
Bellingcat said the symptoms were consistent with poisoning with chemical weapons. It said the trio suffered effects after attending talks in the afternoon of March 3.
The Ukrainian negotiators are said to have included Crimean Tatar lawmaker Rustem Umerov. He has since tweeted to say he is "fine", adding: "Please do not trust any unverified information. We have an informational war ongoing as well."
The Kremlin has acknowledged that Abramovich played an early role in peace talks between Russia and Ukraine, but that the two teams have since taken over negotiations.
Abramovich was asked to mediate by Ukraine because of his background in Russia, where he made his fortune in the chaotic period of post-Communist privatisations in the 1990s.
He is believed to have been travelling between Russia and Ukraine to help mediate talks between governments to end the war, and was seen at an airport in Israel on March 14.
It is not known who might have been behind the alleged attempted poisoning, but one theory is that it might have been the work of hardliners who wanted the talks to fail and sent an appropriate message.
The oligarch and owner of Chelsea Football Club is considered a close ally of
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