Former Chelsea owner Roman Abramovich and two Ukrainian peace negotiators are said to have suffered symptoms of poisoning, following a meeting in Kyiv.
On the evening of 3 March they met in Kyiv, but later that evening - three of them suffered symptoms of nerve agent poising, according to the investigative website Bellingcat.
Jack Losh is a journalist who has just arrived back in London after spending time in Ukraine.
He spoke to Susie Ferguson.
