MOSCOW—Ksenia Sobchak, a Russian socialite and reality television star turned opposition activist, has caused controversy by selling T-shirts with herself as the Virgin Mary.

The icon motif has been in vogue with opposition activists ever since three members of the punk band Pussy Riot were given two-year prison sentences for a raucous protest in a Moscow cathedral that targeted President Vladimir Putin and his close relationship with the Orthodox Church.

Like Pussy Riot, the T-shirts have offended many believers.

Sobchak said she did not approve of the band members' stunt, but "the punishment they received clearly doesn't fit their crime."

She was selling the shirts at a Moscow department store on Saturday as tens of thousands of anti-Putin protesters marched through nearby streets.