Supporters of Ukraine’s former prime minister Yuila Tymoshenko tussled with police on Friday as the 50-year-old was arrested for contempt of court.
She has been on trial in Kiev for alleged abuse of office for the past six weeks.
The opposition leader has repeatedly insulted the judge throughout the case and denounced the proceedings as politically motivated.
Tymoshenko told reporters outside the court earlier on Friday that President Viktor Yanukovych had ordered the case in an attempt to silence her.
Prosecutors have been investigating Tymoshenko’s approval of a 2009 gas import deal with Russia.
The opposition leader told euronews earlier this year that the case is “part of Ukraine’s wide-ranging political repression”.
She denies any wrongdoing and says there is no credible evidence against her.
Judicial authorities accuse Tymoshenko of paying over the odds for the gas contracts with Russian energy giant Gazprom.
Her lawyers argue Kiev pays less than other European nations and say the charges have been fabricated in an attempt to bar her from next year’s parliamentary elections.