Topless feminist FEMEN came out to support Russian punk band Pussy Riot as part of a series of demonstrations around the world aimed at helping the detained trio.
Holding signs saying 'f**k Putin' and 'Free Pussy Riot', the protesters were detained outside Russian consulate in Sao Paulo, Brazil by civil police officers.
Pussy Riot are currently awaiting the result of a hooliganism trial, after performing their single Punk Prayer - which calls for the Virgin Mary to 'throw Putin out' - in a cathedral.
If found guilty the three members - Nadezhda Tolokonnikova, 23, Yekaterina Samutsevich, 29, and Maria Alekhina, 24 – could face up to seven years in prison.
Femen were founded in 2008 in the Ukraine, and their unique form of protest has since spread. The group held demonstrations in London protesting the Olympics' "support" for radical Islamist regimes.
In a separate protest in support of Pussy Riot, the mayor of Reykjavik, Iceland, Jon Gnarr donned a pink dress and lip synced to one of the band's songs.
Sir Paul McCartney has written to Pussy Riot, telling them to "stay strong" and saying he would do everything in his power to help.
In a letter to Nadya, Katya and Masha the Beatles musician wrote:
"I hope you can stay strong and believe that I and many others like me who believe in free speech will do everything in our power to support you and the idea of artistic freedom. Wishing you the very best of luck, Paul McCartney."
The band has also received support from Bjork, who said this week: "As a musician and a mother I would like to express I fiercely don't agree with them being put to jail because of their peaceful protest performance.”
Labour MP Kerry McCarthy, who attended the Pussy Riot trial, wrote in a blog for The Huffington Post UK: "The defence lawyers say that it is not the judge who will decide, it is Putin himself. The world is watching while he makes up his mind."