The Russian Foreign Ministry swiftly reacted to the news about the arrest of Ukraine's former Prime Minister Yulia Tymoshenko on Friday, calling Kiev to guarantee her an unbiased trial, Xinhua reported.
"Court hearing regarding Tymoshenko must be fair and impartial, match all demands of the Ukrainian law, allow all possibilities for defense and maintaining basic norms and rules," the ministry said in a statement posted on its official website.
The ministry stressed that all agreements about gas supply made in 2009 have been signed in strict accordance with national laws of Russia and Ukraine and international law.
Russian and Ukrainian presidents have authorized these deals, the ministry said.
Former Ukrainian prime minister and now opposition leader Tymoshenko was arrested Friday for violations of court processes during her abuse-of-power trial. The prosecution accused Tymoshenko of signing a gas supply deal with Russian gas export monopoly Gazprom in 2009, which allegedly caused damages to the Ukrainian economy.