Political Jekyll and Hyde

VIENNA - What ails Viktor Yushchenko?

As Ukraine's popular pro-Western opposition leader claims victory in hotly disputed presidential elections, the mystery persists over an appearance-altering condition that twice prompted him to check into an Austrian hospital.

Mr Yushchenko was known for his ruggedly handsome, almost movie-star looks. Now his complexion is pockmarked and a sickly green. His face is swollen and part-paralysed. One eye often waters.

He accused the Ukrainian authorities of poisoning him. His detractors suggested he had eaten some bad sushi.

Adding to the intrigue, his Austrian doctors have asked foreign experts to help to determine if his symptoms may have been caused by toxins found in biological weapons.

Medical experts said they might never know for sure what befell Mr Yushchenko. But the condition, whatever it was, has dramatically changed his appearance since he first sought treatment at a private Vienna clinic on September 10.

He had a week of intensive treatment for acute pancreatitis as well as a viral skin disease and nerve paralysis on the left side of his face.

Clinic director Michael Zimpfer said doctors could not explain some of the symptoms, particularly his strong backaches. They could not rule out stress or a viral infection.

Dr Zimpfer and the clinic's chief physician, Dr Lothar Wicke - who requested police protection after receiving an anonymous threat while treating Mr Yushchenko - later asked for help from "a specialist in military operations and biological weapons", the Austria Press Agency reported.

By the time Mr Yushchenko checked out of the clinic last month after returning for followup treatment, doctors said they could neither prove nor rule out that he had been poisoned.

John Henry, a toxicologist at Imperial College, London University, said photographs indicated that Mr Yushchenko might have chloracne, a type of adult acne caused by exposure to toxic chemicals.