"He did not drink alcohol yesterday and did not take any pills today", Yarmysh wrote on Telegram.
Meanwhile, the regional branch of the Russian Health Ministry said that Navalny's transportation from Omsk is not under consideration.
"The issue of transporting Alexei Navalny from Omsk is not yet being considered", the spokeswoman said.
The ministry reiterated that the country's leading health specialists could be involved in the consultations, but so far there has been no need for that.
Navalny was on a flight from the Siberian city of Tomsk to Moscow when he fell gravely ill earlier in the day. The plane made an emergency landing in the city of Omsk, where Navalny was hospitalised and put on a ventilator in a coma. According to the deputy chief doctor of the hospital, Anatoly Kalinichenko, Navalny is in stable condition but still in intensive care. His spokeswoman believes that he has a toxic poisoning. The hospital said that this was just one of the possible reasons behind Navalny's illness.