Ukrainian former president Viktor Yushchenko told a Kiev court on Wednesday that Russian Prime Minister Vladimir Putin should be summoned to give evidence in the trial of his one-time premier Yulia Tymoshenko.
He also urged the court to summon Alexey Miller, the CEO of Russian energy giant Gazprom.
Tymoshenko is on trial on abuse of office charges in connection with a "disadvantageous" 2009 gas deal she signed with Russia while she was premier of the former Soviet republic. She faces 10 years behind bars if found guilty.
Yushchenko - who began testifying on Wednesday morning - said it would be "impossible to establish the truth" without Putin and Miller. Both men were involved in 2008-2009 gas talks with a Ukrainian delegation led by Tymoshenko.
Yushchenko also said Tymoshenko, a former ally, was too hasty in the signing of the gas contracts with Russia and failed to protect Ukraine's national interests.
"We had 24 billion cubic meters of gas in stock, enough to provide the whole country with gas until May," the Ukrainian ex-leader said in the courtroom, when asked about the deal, struck in early 2009.
Yushchenko said he had asked Tymoshenko not to attend the Moscow gas summit in 2009 and she agreed. However, later Tymoshenko headed to the event and struck a deal with Gazprom to buy gas for $450 per 1000 cubic meters. A 20% discount later brought down the price to $360.
"This was a shock for me" Yushchenko said, adding that he believes that Russia should sell gas to Ukraine for $200 per 1000 cubic meters.
Currently Ukraine's leading opposition figure, Tymoshenko has denied all the charges against her, saying they are politically motivated.
