Law enforcement officers reportedly raided the home of an activist who works for opposition firebrand Alexei Navalny's Anti-Corruption Fund on Wednesday.
The raid's target, Georgy Alburov, said via Twitter that Russia's Federal Security Service searched his residence in connection with the alleged theft of a painting by artist Sergei Sotov.
The painting was discovered a month prior during a raid on Navalny's apartment.
Alburov had already been summoned by Russia's Investigative Committee over the theft of the painting in late June.
Sotov, the artist, said he had not approached the police and did not have any claims against Navalny.
Alburov said his apartment had been searched without a warrant and that law enforcement agents had confiscated two laptops and other electronics.
Investigators claim that Sotov's painting, which had been on display in the city of Vladimir, was stolen by an unidentified person.
Earlier this month, Navalny refused to provide a testimony regarding the theft of the painting, a case which he claimed had been fabricated.
Navalny, who ran in Moscow's 2013 mayoral race, is currently under house arrest in connection with an embezzlement case brought against Navalny and his brother by cosmetics giant Yves Rocher Vostok.