The wife of a prominent Russian opposition figure who has been hospitalized for a week with a mysterious illness says he has regained consciousness.

Vladimir Kara-Murza, a journalist and a close associate of the murdered opposition leader Boris Nemtsov, was hospitalized in a grave condition last week after suddenly falling ill. He reportedly was suffering kidney failure.

No cause for the illness has been determined. But in light of the fatal poisoning of defector Alexander Litvinenko and the mysterious deaths of other Russian opposition figures, some worry that Kara-Murza could have been poisoned.

The Open Russia organization cited Evgenia Kara-Murza as saying Tuesday that her husband "has opened his eyes and recognized his relatives."