ST. PETERSBURG, September 6 (RIA Novosti) – A lawyer who was observing a court case involving members of a provocative performance art group Thursday was detained by police for filming the proceedings, a Russian Interior Ministry spokesperson said.

Svetlana Ratnikova was in court as a spectator during proceedings against Igor Chepkasov and Marina Kuznetsova, two members of the Voina (War) group, who were arrested in St. Petersburg Wednesday.

“During the session, a judge’s secretary suddenly said that Ratnikova was recording video on her phone,” Dinar Idrisov, the lawyer representing the Voina defendants, told RIA Novosti.

Police confirmed Ratnikova is in police custody “in connection with an administrative charge.”

A group of activists from Voina entered the city's Muzei Vlasti (Museum of Authority) Wednesday and seized a several-meter-long picture depicting the leaders of the G20 summit, which is currently taking place in a St. Petersburg suburb.

The activists took the picture out into the middle of Nevsky Prospekt, one of the city’s major thoroughfares, and blocked traffic for several minutes.

“Art should belong to the people,” Chapkasov, one of the Voina members involved, told journalists after entering the museum.

Thursday’s court session was considering two charges against Chapkasov - disorderly conduct during a rally and disobeying a lawful police order.

Voina has carried out a string of politically-charged and controversial public stunts, pranks, and performance art, including staging an orgy inside the Moscow Biological Museum, and attempting to release thousands of giant cockroaches inside a Moscow courthouse.

The group won a contemporary art award sponsored by Russia’s Culture Ministry in 2011 for painting a 65 meter (210-foot) image of a penis on a St. Petersburg drawbridge.