( CNN ) -- A judge on Saturday postponed the tax evasion court hearing of former Ukrainian Prime Minister Yulia Tymoshenko , who is serving a seven-year prison sentence following last year 's conviction of abuse of authority . Judge Konstantin Sadovsky postponed the hearing until May 21 , ruling that Tymoshenko could not be tried in absentia , the Ukrainian State News Agency reported . Tymoshenko did not attend the hearing because of `` massive back pain , '' according to the news agency . The judge 's ruling follows reports that Tymoshenko was roughed up in prison . The two-time prime minister said Tuesday she was beaten unconscious in prison last week , but the prosecutor said his office investigated her claim and found no proof to substantiate her allegations . But EU foreign policy chief Catherine Ashton said Tymoshenko 's claim had been confirmed by the Ukrainian Ombudsperson 's Office . Tymoshenko was `` subjected to physical violence during the transfer from her cell to a hospital on 20 April , '' read a statement released Thursday by Ashton 's office . Ashton called on Ukraine `` to examine promptly and impartially any complaints of torture or other forms of cruel , inhuman or degrading treatment , '' according to the statement . Tymoshenko went on a hunger strike after the beating to draw attention to `` violence and lack of rights '' in her country . Ashton 's statement said she is `` seriously concerned '' about Tymoshenko 's hunger strike . She asked Ukraine to allow the EU ambassador and independent medical specialists to visit the former prime minister in prison . Tymoshenko said she was discussing with officials a transfer to a hospital for health reasons before the beating . In a statement , Tymoshenko said that after her cell mate left the cell , `` three sturdy men '' entered , threw a bed sheet over her , dragged her off the bed and applied `` brutal force . '' `` In pain and despair , I started to defend myself as I could and got a strong blow in my stomach through the bed sheet , '' she said in a statement . Tymoshenko was dragged `` into the street , '' she said . `` I thought these were the last minutes of my life . In unbearable pain and fear I started to cry and call out for help , but no help came . '' She fell unconscious , and when she came to , she was in a hospital ward , she said . Last October , a Ukrainian court found Tymoshenko guilty of abuse of authority for signing overpriced gas contracts with Russia and sentenced her to the seven-year prison term . The prosecutor said the gas deals inflicted damages to the country amounting to more than 1.5 billion hryvnas ( almost $ 190 million at the current exchange rate ) . The court ruled she must repay the money . Amnesty International has slammed the verdict as `` politically motivated '' and called for the release of Tymoshenko , who was prime minister from January to September 2005 and December 2007 to March 2010 . CNN 's Zarifmo Aslamshoyeva contributed to this report .
A judge has postponed a court hearing for Yulia Tymoshenko until May 21 . Judge Konstantin Sadovsky ruled the former prime minister can not be tried in absentia . Tymoshenko did not attend the hearing because of back pain , state media reported . Tymoshenko is serving seven years in prison for abuse of authority .