Russian billionaire Roman Abramovich and Ukrainian peace negotiators have recovered from a suspected poisoning, according to the Wall Street Journal. Abramovich and the negotiators believe the incident happened in early March, during peace talks in Kyiv.

“The victims blamed the suspected attack on hard-liners in Moscow who they said wanted to sabotage talks to end the war,” the Wall Street Journal reported.

“A spokesman for Mr. Abramovich previously said he was playing a “limited” role in trying to find a “peaceful resolution” between the two countries,” the BBC reported.

Three in the group of four developed various symptoms, including red eyes, peeling skin, and eye tearing, according to the report. 

“The experts concluded that the symptoms are most likely the result of international poisoning with an undefined chemical weapon,” Bellingcat, a Netherlands-based investigative journalism group, tweeted. The three people who suffered symptoms consumed only water and chocolate in the hours before they started feeling sick. A fourth person consumed the same items but did not develop symptoms.

“The experts said the dosage and type of toxin used was likely insufficient to cause life-threatening damage, and most likely was intended to scare the victims as opposed to cause permanent damage,” Bellingcat wrote. “The victims said they were not aware of who might have had an interest in an attack.”

Abramovich has been sanctioned by the United Kingdom. President Joe Biden is considering sanctions against Abramovich as well, according to reports. The Wall Street Journal reported Ukrainian President Volodymyr Zelenskyy asked Biden not to place sanctions on the Russian billionaire given concerns that the measure would impact peace talks.