Punk group Pussy Riot's fight against Russia at the European Court of Human Rights in Strasbourg will be joined by several prominent rights organizations, a news report said.
Rights groups Amnesty International, Human Rights Watch, Article 19 and the American conservative Christian group Alliance Defending Freedom will all give testimony in the case, Pavel Chikov of the Agora human rights group, which represents Pussy Riot at the ECHR, told Vedomosti.
Pussy Riot rose to fame after band members Maria Alyokhina and Nadezhda Tolokonnikova were arrested for singing an anti-Putin song at Moscow's Orthodox Christ the Savior Cathedral in 2012.
Tolokonnikova and Alyokhina filed a complaint at Europe's top human rights court after being convicted in August 2012 and sentenced to two years in prison on hooliganism charges. They were freed under a presidential amnesty late last year.
The Alliance Defending Freedom, an Arizona-based group was the first party to file an amicus brief in the case in support of the Russian authorities' defense of traditional values in light of reported discrimination against Christians in Europe, Chikov said.
Chikov said the rights organizations' argument in defense of freedom of speech has broadened the relevance of the case from a national affair to a global clash between traditional values and liberties.
The ECHR occasionally receives letters from third parties regarding cases but rarely lets them take part in hearings, Vedomosti said.