KIEV, Jan. 12 – The Russians admitted they used to produce the type of dioxin used 3.5 years ago to poison Viktor Yushchenko, then an opposition leader, but later discontinued production, Ukrainian Prosecutor General Oleksandr Medvedko said.

But Russia also denied having any officially recorded exports of that type of dioxin, Medvedko said, citing a recent letter from Russia’s Prosecutor General Office.

“It [dioxin] used to be produced in Russia in the past, but it had never been exported,” Medvedko said in an interview with Ukrayinska Pravda online newspaper published Saturday, citing the letter. “Russia said it currently doesn’t produce dioxin of [that] formula.”

The response provides a glimpse at the progress of the investigation into the poisoning of Yushchenko, then the leading opposition candidate, in the runup to Ukraine’s presidential election in November 2004.

Yushchenko, a pro-Western figure who campaigned on pushing Ukraine closer to the European Union, had faced unprecedented pressure from the government, which was strongly backing a pro-Russian candidate.

The poisoning, which nearly killed Yushchenko in September 2004, slowed his campaign significantly. He was treated for almost two months in a private Vienna-based hospital during the busiest time of the campaign.

Toxicology experts said three countries--the US, Britain and Russia--could have actually produced the type of dioxin used to poison Yushchenko.

The US and Britain cooperated with Ukraine’s investigation by providing their samples, which had never matched those found in Yushchenko’s blood.

Russia has refused to cooperate in the investigation for the past three years. Last year Russia suddenly asked Ukraine to submit the formula of dioxin found in Yushchenko’s blood, and said it would check it against its dioxin samples.

The latest response from Russia leaves many questions unanswered. It is still unclear whether Russia produced this type of dioxin in 2004, when the poisoning had actually taken place.

“This is what we are trying to find out,” Medvedko said, adding he will soon send another letter to Russia seeking this and other answers.

Yushchenko first fell ill after having dinner with Ukrainian Security Service chief Ihor Smeshko and his deputy, Volodymyr Satsyuk, on Sept. 5, 2004. He reported having a headache about three hours after the dinner, and by the next day had developed an acute stomachache.

Yushchenko, who was rushed to a Vienna hospital on Sept. 10, later reported pancreatitis and gastrointestinal pain, as well as backache. He also suffered partial nerve paralysis in his face and an inflammation of one inner ear.

About three weeks after his first symptoms, he developed the rough, acne-like rash on his face which is the hallmark of dioxin poisoning.

Satsyuk, who hosted the dinner, and his assistant, who had been serving food on the table, are thought to have later escaped to Russia, which has refused to trace them down to help the investigation.

“We narrowed down the list of suspects to four or five, and perhaps soon we will solve the issue of instituting criminal proceedings,” Medvedko said. “This year we will put a period in the investigation.” (tl/ez)