Photo: WENN.com

Concerns are growing for the safety of Pussy Riot member Nadezhda Tolokonnikova, who has not been heard from in nearly three weeks and whose whereabouts are unknown.

The jailed punk band member is believed to have gone missing during a prison transfer to Siberia as she continues to serve time in jail for a political protest which took place in 2012.

Her worried husband is leading the search for Tolokonnikova, who disappeared between Moscow where she initially serving her jail sentence and Siberia - which 4,500km east of Moscow. There are concerns for her wellbeing as she had been on hunger strike prior to her move to the remote penal camp.

Pyotr Verzilov has brought the situation to internation attention on social media, travelling to the hostile Siberian prison where he believed she was being held in the snowy Krasnoyarsk region.

"The administration of IK-50 [prison] in the middle of the taiga [virgin forest] told us today that 'We don't have Tolokonnikova here and don't know when she'll arrive,'" he wrote on Twitter. "19 days without any contact with Nadya."