Ukrainian former prime minister Yulia Tymoshenko (R) embraces a supporter before entering the state prosecutor's office in Kiev May 24, 2011.  [Photo/Agencies]

KIEV - Ukrainian prosecutors accused former Ukrainian prime minister Yulia Tymoshenko on Tuesday of hampering investigations for her trial on charges of abuse of power and threatened her with arrest.

The Batkivshchyna Party said Tymoshenko, 50, a fierce opponent of President Viktor Yanukovich, was questioned at the state prosecutor's office in a room guarded by dozens of masked police officers.

The prosecutor said Tymoshenko, who argues charges against her are politically motivated, had been allowed to leave after the meeting with investigators; but a court order had been issued providing for her arrest at any time if deemed necessary.

"The investigator could have detained her today but since she (duly) arrived for questioning together with her lawyer the investigator went ahead with... procedures without detention," a spokesman for the prosecutor's office said.

Prosecutors said in a statement that Tymoshenko, charged with abuse of office over carbon permit sales and the purchase of emergency rescue vehicles, had "for a long time evaded pre-trial investigation and disrupted investigative measures concerning her".