VIENNA, Dec 8 (AFP) - Austrian doctors who treated Ukrainian opposition leader Viktor Yushchenko for unusual symptoms in September said Wednesday they were mulling three theories related to poisoning, although they had no proof it had taken place.
"We are working on three theories which are all three related to poisoning," said Nikolai Korpan, a surgeon of Ukrainian descent who treated the opposition presidential standard bearer in an upscale private clinic here.
"The first of the three theories involves dioxin or endotoxin poisoning," added Korpan, who would not elaborate on the two others, citing medical confidentiality.
The head of the Vienna clinic, Michael Zimpfer, had earlier said there "was no evidence of poison" and that, while new medical analyses had been ordered from US and European labs, "so far there is no proof" of poisoning.
"Poisoning without evidence is a bit like a murder without a body," he told a news conference.
Zimpfer was responding after Korpan was quoted by The Times newspaper in London as saying that specialists had established the opposition leader had been the victim either of a biological or chemical agent or, more likely, a rare poison.
Korpan was quoted as saying that Yushchenko "received this substance from other people who had a specific aim."
Zimpfer said that while anything was possible, nothing had been established beyond doubt.
"Until now we have only undertaken a descriptive diagnosis," he added, and the symptoms "do not correspond to the clinical image of an illness."
Korpan, in a telephone interview with the Austrian news agency APA, denied telling The Times that poison had been confirmed.
"To this date suspicions of poisoning have been neither confirmed nor ruled out," he told APA.
The mystery of Yushchenko's ill health rose to the fore when he fell ill ahead of his country's presidential elections last month.
He was admitted in September to Viennas Rudolfinerhaus clinic complaining of violent stomach pains and suffering from lesions to his face and body, and remained there until September 19.
Viennese doctors were unable to explain the swelling of Yushchenko's liver, pancreas and intestines.
When he re-emerged weeks later in Ukraine the voters gasped at seeing a man who appeared to have aged by at least a decade seemingly overnight.
He looked gaunt, his skin yellowish, sagging and covered in pockmarks. One of his eyes tended to swell and water and he appeared tired and unwell.
12/08/2004 17:05 GMT - AFP