Pussy Riot’s Nadezhda Tolokonnikova has been placed in solitary confinement at Penal Colony No 14, according to Amnesty International, following her whistle blowing open letter about alleged abuses at the detention facility.

The human rights organization is calling for an investigation into the abuses Tolokonnikova wrote about. The detention facility where she is serving a two-year sentence for “hooliganism motivated by religious hatred” is located in the Mordovia region, southeast of Moscow.

Tolokonnikova’s open letter began circulating via the internet earlier this week and was published  on The Guardian website.

“The prison administration claimed that Nadezhda Tolokonnikova had been placed in isolation for her own protection, but we are concerned this could be yet another punishment for demanding that her own rights and the rights of other inmates are respected,” Sergei Nikitin, Director of Amnesty International’s office in Moscow, said in a statement on the Amnesty website. “What authorities should do is investigate the allegations she made.”

“The case against members of the band Pussy Riot has been consistently outrageous from start to finish,” Nikitin continued, “and sought nothing other than to undermine the band members’ right to freedom of expression. The Russian authorities must immediately and unconditionally release the activists and quash all charges against them.”

For more, go to the Amnesty International site.