Ukraine's jailing of former prime minister Yulia Tymoshenko was a politically motivated violation of her rights, the European Court of Human Rights has ruled.
A Ukrainian government official stormed out of the court after the decision in a case that has strained the former Soviet state's ties with Europe and the United States.
Ms Tymoshenko, an architect of Ukraine's 2004 pro-democracy Orange Revolution, was sentenced to seven years in prison in October 2011 after being convicted of exceeding her powers as premier while negotiating a gas contract with Russia.
She says her jailing was intended to keep her out of politics and that her rights were violated. The court found unanimously that her detention in August 2011 was arbitrary.It is unclear if a decision by the European court would be legally binding in Ukraine.
Serhiy Vlasenko, Ms Tymoshenko's lawyer, said the court found "the prosecution of Mrs Tymoshenko in Ukraine had nothing to do with the law, had nothing to do with democratic standards, had nothing to do with a criminal prosecution."
In Kiev the government representative with the European Court of Human Rights said it needed time to study the ruling but suggested the government might appeal.
Ms Tymoshenko and her allies - including Mr Vlasenko, who was expelled from parliament - claimed that her jailing was masterminded by president Viktor Yanukovych, who is afraid of the country's top opposition leader and is intent on keeping her locked in jail, out of politics and out of last year's parliamentary elections and out of the 2015 presidential election.
Mr Yanukovych has said it was a legal matter he could not interfere with. Over the weekend, a presidential commission said it would not consider a pardon for Ms Tymoshenko while other legal cases against her are continuing - including some that could take years to resolve.
The dilemma faced by the West is whether to bring Ukraine closer into its fold, despite Ms Tymoshenko's case, or risk seeing the country move toward Russia.Mr Vlasenko called for Ms Tymoshenko to be freed immediately, saying that was the only way to restore her rights. "She is under the 24-hour a day, 7 days a week, 365 days a year, psychological pressure," he said.
If the decision is upheld on appeal, Ms Tymoshenko's legal team could petition Ukraine's Supreme Court to annul the conviction and seven-year sentence on the grounds that it was issued by the same judge who ordered her arrested.