Dioxin poisoning caused the mysterious illness of Ukrainian opposition leader and presidential candidate Viktor Yushchenko, doctors said Saturday, adding it could have been put in his soup.
Yushchenko is now in satisfactory condition and his dioxin levels have returned to normal, Dr. Michael Zimpfer, director of Vienna's private Rudolfinerhaus clinic, told a news conference. Dr. Nikolai Korpan also said "no functional damage will remain."
"There is no doubt about the fact that Mr. Yushchenko's disease has been caused by a case of poisoning by dioxin," Zimpfer said.
"We suspect involvement of an external party, but we cannot answer as to who cooked what or who was with him while he ate," Zimpfer said, adding that tests showed the dioxin was taken orally.
Zimpfer said Yushchenko's blood and tissue registered concentrations of dioxin 1,000 times above normal levels.
"It would be quite easy to administer this amount in a soup," Zimpfer said.
Tests run over the past 24 hours provided conclusive evidence of the poisoning, Zimpfer said.
When first seen by the Austrian doctors, Yushchenko was in a "critical stage" but was "not on the verge of dying," Zimpfer said.
"If this dose had been higher, it may have caused death," Zimpfer said.
Dioxin is formed as a by-product from industrial processes such as waste incineration, chemical and pesticide manufacturing and pulp and paper bleaching.
They are a normal contaminant in many foods, but a single high dose, usually in food, can trigger illness, London-based toxicologist John Henry said last month.
Shortly after the announcement of the diagnosis on Saturday, Henry told British Broadcasting Corp. television that Yushchenko's case was, in his experience, unique.
"We've never had a case like this, a known case of large, severe dioxin poisoning ... It's normally fairly mild. It can cause liver damage."
"It's usually low-level, long-term poisoning. A very large dose, nobody has any real idea of what it would cause. Now we do know."
Yushchenko first fell ill in September and was rushed to the elite Vienna hospital. He resumed campaigning later in the month but with a pockmarked and badly disfigured face.
He returned to the hospital later in September for further treatment and checked in for a third time Friday.
Yushchenko has accused Ukrainian authorities of trying to poison him in the runup to a presidential vote marred by fraud. Ukraine's Supreme Court voided the outcome of that vote, which Yushchenko lost to Prime Minister Viktor Yanukovych, and a rerun of the ballot is slated for Dec. 26.
Arriving at the hospital Saturday afternoon, Yushchenko's wife Kateryna Chumachenko said she was convinced from the start that her husband was poisoned.
"I knew from the very beginning he was poisoned," she said. "We had received threats before it happened, and we continued to receive threats because I think there are many people who consider my husband and the changes he would bring to Ukraine a threat to them personally."
Yushchenko had arrived at the hospital Friday evening in a convoy of three cars, surrounded by bodyguards and accompanied by his wife.
"Everything is going well. I plan to live for a long time and I plan to live happily. I am getting better health every day," Yushchenko said on arrival.