Doctors say it's "highly likely" Peter Verzilov of Pussy Riot was poisoned, suffering from amnesia

Doctors at Berlin's Charite Hospital have told reporters at a press conference on Tuesday that they believe Peter Verzilov was poisoned, though it's unlikely they will be able to determine the exact compound.

The member of Russian activist punk group Pussy Riot lost his eyesight and speech and ability walk within a two hour period last week when he appeared in court with other members of the band.

German doctors from Charité Universitätsmedizin Berlin hospital, Prof. Dr. Karl Max Einhäupl (CEO) and Prof. Dr. Kai-Uwe Eckardt, told press that they, as well as Russian doctors at Sklyfosovsky hospital, believe his symptoms look like effects of poisoning by anticholinergic agent, which disrupts the nervous systems that regulate inner organs.

It is “highly probable that he was poisoned,” confirmed Eckardt at the news conference.

They have not specified the exact compound (there are 40 or 50 of them) "and may not be able to identify," added Einhäupl.

Eckardt explained that their conclusion is based on information from relatives as well as the Moscow hospital where he was initially treated last week, along with other symptoms such as disorientation and widened pupils.

Verzilov was initially treated in Moscow before being rushed to Berlin on Saturday night. His ex-wife Nadia Tolokonnikova was travelling with him, and posted a video online that shows him being carried from a private plane.

"The benefits of anticholinergic drugs for those who want to poison someone is that they don’t last long in blood and urine, and in a few days they are gone (which means that German doctors may not find the exact compound used in the poisoning)," reads a statement from Tolokonnikova.

A possible compound from anticholinergic group, suggests Tolokonnikova's statement, is scopolamine - also known as “Devil’s breath” - commonly used as a date-rape drug. It is tasteless, scentless, and is easily added to food and drink.

It is unlikely doctors will be able to determine the exact substance used, as almost a week has passed.

"We wish we could get a comment from Peter about his poisoning, but we cannot since he’s still disoriented and not fully with us as the Peter we know. He’s dizzy and confused, he cannot remember where he is right now," she continues.

While Verzilov is currently suffering amnesia, doctors say the effects are reversible. Amnesia is a known side-effect of scopolamine.

Einhäupl added that Verzilov is improving "from day to day and he is no longer in life-threatening danger," though he continues to receive intensive care.