Ion Iliescu, Romania's president, has been forced to appeal to his old university, the Institute of Power Engineering in Moscow, to provide proof that he was not recruited by Stalin's secret police while he was a student in the Soviet capital.
Iliescu studied water management and ecology in Moscow from 1950 to 1954 after his first degree in his own country.
Recruiting foreign students, including those from "fraternal" socialist countries, as informers and agents was a standard KGB practice.
But Mr Iliescu denied that he was recruited or even approached, after the allegations surfaced in the Romanian daily newspaper, Ziua, which cited two individuals at the institute as sources for its claim.
"I have never had any kinds of contact and I could not be recruited either by Romanian or foreign special services," he said in a television interview.
The Romanian embassy in Moscow had made an official application to the institute and had received an answer which, he said, proved the allegations were a "fantasy".
The next day the proof was disclosed to the Rompress news agency - a document from the institute archives stating that the two persons mentioned by Ziua as its sources had neither worked nor studied there.