"All the falsifications in the election were sanctioned by Kuchma and he ... used administrative resources to discredit Yanukovych," Chornovil said.
Yanukovych did not know "anything about election falsifications," Chornovil told The Associated Press.
Chornovil also alleged that Kuchma's billionaire son-in-law, Viktor Pinchuk, was financing Yushchenko's election campaign.
He also insisted that Yanukovych would not resign as prime minister, but had taken a leave of absence so "that no one may accuse him of using administrative resources and pressuring voters."
Taking leave also appeared to be a safeguard against firing, because Ukrainian law bans the dismissal of presidential candidates from their jobs.