One US-based Russian woman reports a strange smell in her hotel room and then falling ill in the hours afterwards, but says doctors couldn't find anything wrong with her.
German police are investigating reports that at least two Russian exiles fell ill around the time they attended a conference in Berlin in April linked to a Russian opposition figure.
Berlin police confirmed their investigation in an email responding to a query by The Associated Press, but wouldn't give any details. The probe is being conducted by a police unit that handles politically motivated crimes.
The Russian media outlet Agentstvo reported that two participants in an April 29-30 conference organised by Russian opposition figure Mikhail Khodorkovsky experienced health problems around the time of or after the event.
Natalia Arno, head of the US-based Free Russia Foundation, said in a 16 May Facebook post that she woke up with acute pain and strange symptoms during a trip to two European cities before she returned to the United States. There is some suspicion that she was poisoned, possibly by a nerve agent, Arno said in the post.
Arno said she experienced "strange symptoms" which at first she attributed to jetlag, lack of sleep and general fatigue.
However in the second city of her trip she claims she found her hotel door open, and inside "immediately felt a foreign and sharp smell of cheap perfumes in the room."
Arno said she woke early the next morning "in acute pain and strange symptoms" and on the flight back to the US, she felt numb and ended up in a hospital emergency room when she landed but that doctors couldn't immediately find anything wrong with her.
In a second case, Agentstvo reported that a journalist it didn't identify may have developed symptoms before the meeting organised by Khodorkovsky.
Germany's Welt am Sonntag newspaper first reported on the investigation by German police.