It quoted on Friday Ukraine's prosecutor-general Svyatoslav Piskun as saying 18 X-55 cruise missiles, also known as Kh-55s or AS-15s, were exported in 2001, although none was exported with the nuclear warheads they were designed to carry.
The X-55 had a range of 3000km, enough to put Japan within striking range of the Asian continent or to reach Israel from Iran, said the newspaper, adding Piskun's statement was the first confirmation by a government official of the exports.
The news of the missile exports came less than three months after Ukrainians elected a new Western-leaning president, Viktor Yushchenko, to lead the former Soviet republic.
The United States has long expressed concern that parts of the former Soviet Union's nuclear arsenal could be sold or smuggled to countries that it regards as a potential danger.
Piskun said the previous Russian-backed government arrested and charged a Ukrainian businessman over the exports and initiated a secret trial last year. Two Russian businessmen were suspected of masterminding the sale, one of whom was arrested in Prague last July and was under an extradition request, he said.
Viktor Yushchenko (L) wants to
steer Ukraine towards the EU
The Financial Times quoted the US embassy in Kiev as saying it was "closely monitoring" a Ukrainian government investigation into the case and wanted the findings of the secret trial made public.
The United States accuses Iran of trying to secretly develop a nuclear weapons programme. Tehran denies the charge, saying its nuclear programme is only for power generation.
Piskun was quoted as saying he understood Japan was concerned that the missiles delivered to China could have ended up in North Korea, although there were no grounds to suspect such a transfer.
Yushchenko wants to steer Ukraine towards membership of the 25-nation European Union, which expects to lift an arms embargo against China by the end of June.