Ukrainian Prime Minister Yulia Timoshenko arrives at the Prosecutor-General's Office in Kyiv, Sept. 11. Tymoshenko will be questioned as a witness in an investigation into the 2004 dioxin poisoning of President Viktor Yushchenko. AP Ukraine's fiery prime minister says the investigation into the unsolved dioxin poisoning of President Viktor Yushchenko has been completely politicized.

Yulia Tymoshenko spoke as she arrived for questioning by prosecutors into the 2004 incident that nearly killed Yushchenko and disfigured his face.

She suggested Thursday that she's being targeted because she's a potential competitor to Yushchenko in the 2010 presidential elections.

The two were partners in the 2004 Orange Revolution that catapulted Yushchenko to the presidency.

But their tug-of-war has now ruined their coalition and put the county on the brink of its third parliamentary election in as many years. Yushchenko has suggested the poisoning may have been orchestrated by Russia.