Russian Oligarch Roman Abramovich has reportedly suffered symptoms of suspected poisoning.
The Chelsea owner fell ill along with Ukrainian peace negotiators, in an attack blamed on hardliners in Moscow who they say want to sabotage their talks to end the war.
Symptoms included red eyes, constant and painful tearing, and peeling skin on their faces and hands, sources claim.
Abramovich has been shuttling back and forth between Moscow and Lviv in western Ukraine since the start of the war.
President Zelensky, who has met with Abramovich in recent weeks, was reportedly unaffected.