MOSCOW, February 1 (RIA Novosti) – A jailed member of the female punk band Pussy Riot, Nadezhda Tolokonnikova, has been sent to hospital for a medical examination, the Russian prison service said on Friday.

"Tolokonnikova was sent to a hospital at her own and her lawyer’s request,” a Federal Prison Service spokesperson told RIA Novosti, confirming media reports stating she was in hospital. The service did not elaborate, citing patient confidentiality.

Yekaterina Samutsevich, another Pussy Riot member, told Dozhd television that Tolokonnikova has been suffering from headaches. Samutsevich said her friend’s health problems started before she was convicted in August and could be a symptom of a serious illness.

“Back in spring 2012 Nadezhda was repeatedly complaining of headaches when she was in pre-trial detention,” Tolokonnikova's lawyer Irina Khrunova, said in written comments sent to RAPSI news agency on Friday. “In prison conditions, the pain has got worse,” she said.

Earlier medical tests on Tolokonnikova could not reveal the cause of her health problems and she is in need of a proper diagnosis, Khrunova added.

Tolokonnikova, 23, and another band member Maria Alyokhina, 24, are serving two-year terms for "hooliganism motivated by religious hatred" for performing an anti-Kremlin “punk prayer” at Moscow's Christ the Savior Cathedral last February.

Samutsevich was given a suspended sentence.

Earlier version of the story was updated with lawyer's comment.