Pussy Riot documentary premieres at Sundance Film Festival

A documentary following the trial of Russian protest punk band Pussy Riot has premiered at the Sundance Film Festival.

Maria Alyokhina, 24 and Nadezhda Tolokonnikova, 22, were convicted of "hooliganism motivated by religious hatred" over the obscenity-laced "punk prayer" against President Vladimir Putin, which they performed at the Christ the Saviour Cathedral on 21 February 2012.

They were given a two year jail term and the band's third member, Yekaterina Samutsevich, was freed with a suspended jail sentence.

Directors, Maxim Pozdorovkin and Mike Lerner, said they wanted to make a "thought provoking film" about the group.