The wife of a Russian opposition activist who was taken to hospital last week after a sudden illness has said her husband was poisoned.
Vladimir Kara-Murza Jr, a journalist and close associate of murdered opposition leader Boris Nemtsov, was taken to hospital last week with a sudden illness reminiscent of a mysterious poisoning he suffered two years earlier when he nearly died from kidney failure.
No cause for that has been determined.
In light of the fatal poisoning of defector Alexander Litvinenko and the mysterious deaths of other Russian opposition figures, some worried that Mr Kara-Murza could have been deliberately poisoned.
Mr Kara-Murza's wife, Yevgenia, said doctors have told her that her husband, who has been in a medically induced coma for several days, has now been diagnosed with an "acute poisoning by an unidentified substance".
She said the family sent blood samples to a private laboratory in Israel to determine the toxin.
She would not speculate on the nature of the poisoning before those results are available.
Mr Kara-Murza's lawyer Vadim Prokhorov said in a Facebook post that police had confirmed the diagnosis as poisoning by an unidentified substance.