Two men are both claiming to be the legitimate prosecutor general, a powerful job that oversees politically charged investigations such as last year's election fraud, the 2000 killing of journalist Georgy Gongadze and President Viktor Yushchenko's poisoning.
Yushchenko sacked Prosecutor General Svyatoslav Piskun in October, accusing him of "ineffective work," and named a new prosecutor general, Oleksandr Medvedko, who was later approved by parliament.
Piskun sued and a court last month ordered him reinstated. Yushchenko ignored the ruling, alleging that corruption was behind it, and security guards at the prosecutor's office have refused to let Piskun into the building.
Another court decision, made public Dec. 5, declared Medvedko's appointment invalid, and called again for Piskun to be reinstated.
Oleksiy Bebel, spokesman for the Prosecutor General's Office, said "the ruling was made with gross and evident violations of the law."
The prosecutor's office, which appealed, noted that the ruling was made by one judge, Judge Tatyana Ostapchuk, while law dictates that a three-judge panel must consider legal questions concerning the president's actions.
"There is a prosecutor general in Ukraine and it is Oleksandr Medvedko," Bebel said.
Piskun, who also served as prosecutor general under former President Leonid Kuchma, had called his dismissal politically motivated. He argued that he was fired because he opened a criminal investigation into a close Yushchenko ally - an investigation that was closed immediately after Piskun's sacking.
Piskun was an unpopular figure, and many of Yushchenko's Orange Revolution supporters criticized the president for not firing him earlier. Losing presidential candidate Viktor Yanukovych, now a popular opposition leader, has accepted Piskun as a candidate representing his party in parliamentary elections in March.