KIEV (Reuters) - Former Ukrainian Prime Minister Yulia Tymoshenko on Wednesday denied new accusations of attempted theft as based on "fake" documents, while wrangling intensified in her trial on abuse-of-office charges.
Tymoshenko, the fiercest rival of President Viktor Yanukovich, faces up to 10 years in prison on charges linked to a 2009 gas deal with Russia and is the target of two other pending criminal cases.
Her case has raised questions over the independence of the judiciary in the former Soviet republic and overshadowed its plans to forge closer ties with the European Union.
This week, Ukraine's state security service SBU said it had launched an additional criminal case linked to the affairs of an energy company once run by Tymoshenko.
The SBU said company executives, together with former government officials, tried to steal $405 million from the state budget.
"The country's top 'spy' has launched a criminal case based on 1996 fakes," Tymoshenko said on her Twitter feed.
"Here's a hint: investigate me for supporting the Golden Horde in the age of the Mongol Invasion."
Tymoshenko, who has served twice as prime minister, has dismissed earlier charges as politically motivated and accused Yanukovich, who narrowly beat her in the 2010 presidential election, of cracking down on the opposition.
Yanukovich says his government is merely fighting corruption.
In Tymoshenko's current trial, which resumed on Wednesday after a short break, the prosecution alleges that Tymoshenko forced the then-head of state-owned Naftogaz to sign a deal with Russia's Gazprom without consulting her government.
Yanukovich's administration says the 2009 agreement was a sell-out of national interests, although it is abiding by the terms.
On Wednesday, Tymoshenko continued to defy the court by refusing to stand when addressing Judge Rodion Kireyev.
Kireyev, visibly irritated, threatened to expel Tymoshenko from the courtroom and had to call for order repeatedly after booing and laughter from her supporters.
He also ruled that the hearings, which have so far aired live on local television, would be closed for live broadcasts during questioning of witnesses.
Since Yanukovich came to power, several former members of Tymoshenko's Cabinet have been prosecuted for alleged offences in office and at least one has fled Ukraine.
Western governments have expressed concern over the possible use of "selective justice" in Ukraine and "the appearance of a political motive" in Tymoshenko's case.
Tymoshenko, 50, rose to prominence as a leader of the 2004 "Orange Revolution" street demonstrations that ultimately doomed Yanukovich's first bid for the presidency but failed to produce a unified new government.
Early last year, frustrated with infighting between Tymoshenko and her former ally, then-President Viktor Yushchenko, voters punished the duo in the presidential election, handing victory to Yanukovich.
Tymoshenko is still one of the most popular politicians in the country but has so far failed to unite other opposition figures around her.
(Writing by Olzhas Auyezov; Editing by Peter Cooney)