"Nothing of this sort has been recorded in the documents of the bodies concerned, the Iranian government has not concluded any such deal," foreign ministry spokesman Hamid Reza Asefi told journalists.

"It's up to the Ukrainian government to give more information if it has any," he added.

Asefi's comments were the first denial by Tehran of a statement made some 10 days ago by Ukrainian President Viktor Yushchenko, speaking to the US television station NBC.

Yushchenko said X-55 missiles, or AS-15 according to NATO classification, were sold illegally to Iran and China under a counterfeit contract naming Russia as the final destination.

No nuclear warheads were sold with the missiles, made in 1987 which have a range roughly of 3,200 kilometers (2,000 miles) and were poorly maintained, according to a Ukranian source familiar with the investigation.

US intelligence officials quoted by NBC said China and Iran each obtained six missiles. Ukrainian officials have offered conflicting accounts of the number of rockets delivered.

Iran most powerful rocket, the Shahab-3, based on North Korean technology, has a declared range of some 2,000 kilometers. A missile able to travel 3,000 kilometres would bring Israel, the arch-enemy of Tehran, in range.