Russian police raided the home of a prominent ally of opposition leader Alexei Navalny on Friday morning. Police arrested Lyubov Sobol at her apartment after she allegedly went to the home of a Russian Federal Security Service officer Konstantin Kudryavtsev earlier this week and knocked on his door. Navalny claimed he had tricked Kudryavtsev into admitting that the Russian security service planned to put poison in his underwear over the summer. The opposition leader is still recovering in Germany from being poisoned months ago.

Sobol is being accused of trespassing “with the use of violence or a threat to use it” and police have begun a probe into the opposition activist. Police also arrested two of Navalny’s employees.