Alexi Navalny’s wife and a top aide visited him in a Berlin hospital where the comatose Russian dissident is being treated by German doctors after a suspected poisoning.

Navalny was flown to Germany on Saturday from Siberia after doctors determined he was stable enough to be brought to the capital’s Charité hospital for treatment.

After his arrival, hospital spokeswoman Manuela Zingl said the 44-year-old would be undergoing extensive diagnostic tests and that doctors wouldn’t comment on his illness or treatment until they were able to evaluate the results.