Dec. 23 (Bloomberg) -- Ukraine's security service denied involvement in the dioxin poisoning of presidential candidate Viktor Yushchenko that caused his facial disfigurement.

``The Security Service of Ukraine has no relationship whatsoever to the deterioration in the state of health of the presidential candidate Viktor Andriyovych Yushchenko,'' the agency, or SBU, the successor to the Soviet-era KGB, said in a statement posted on its Web site today.

Yushchenko told the Associated Press that he could have been poisoned at a Sept. 5 dinner with General Ihor Smeshko, the SBU head, and his deputy, Volodymur Satsyuk, at Satsyuk's dacha, or country house, outside Kiev.

Yushchenko, 50, faces Ukrainian Prime Minister Yanukovych, 53, on Dec. 26 in a rerun of the Nov. 21 second round of the presidential election. Ukraine's Supreme Court annulled last month's election, in which Yanukovych was leading, because it said the vote was marred by widespread fraud.

Yushchenko now leads 53 percent to 42 percent for Yanukovych, according to a poll cited by Yushchenko's Web site. The poll, conducted by the Razumkov Center between Dec. 14 and 19 and using 2,008 respondents throughout Ukraine, has a margin of error of 2.3 percentage points, according to the Web site.

Satsyuk denied that any attempt was made to poison Yushchenko at his house. ``I am ready to meet live on air with Mr. Yushchenko,'' Satsyuk said in an interview with the New York Times. ``I would like him, looking into my eyes, to say he was poisoned at my dacha.''

Dioxin

Arnold Shechter, a University of Texas specialist in dioxin contamination, said he doubted that Yushchenko would have fallen ill so quickly, because dioxin normally takes between three days and two weeks to have an effect, the New York Times reported.

Doctors in Vienna who treated Yushchenko after he fell ill in September said after further tests on Dec. 11 that he had ingested dioxin, which can cause cancer, birth defects and brain damage.

Some tests were conducted at the Free University in Amsterdam, where Abraham Brouwer, professor of environmental toxicology, said Yushchenko had more than 6,000 times the normal concentration of dioxin in his blood, AP reported.

Yushchenko told AP in an interview on Dec. 16 that the poisoning, making his face bloated and pockmarked, was ``a project of political murder.'' The Sept. 5 dinner with the SBU chiefs ``was the only place when no one from my team was present and no precautions were taken concerning the food,'' AP cited him as saying.

In its statement today, the SBU said it was reacting to reports carried in the media and said it had received no ``official document that could give a juridical basis for the establishment of a place or time or fact of the candidate's poisoning.''

The Ukrainian prosecutor general and a commission of the Verkhovna Rada, or parliament, have opened investigations into the charges.

To contact the reporter on this story: Julian Nundy in Paris at jnundy@bloomberg.net

Last Updated: December 23, 2004 07:06 EST