Romania is in the grip of a political storm over the files of the Securitate, the former communist secret police.
The vast Securitate archive has been kept under wraps
President Traian Basescu went on national TV on Wednesday to deny claims that he had worked for the Securitate.
He also defended his decision to have the files opened, saying a failure to do so could jeopardise Romania's bid to join the European Union in 2007.
A special commission is reviewing the Securitate files. Some politicians have been named as former collaborators.
"I did not sign an agreement with the Securitate," Mr Basescu said, insisting that he had only written routine "travel reports" for his superiors when he worked as a ship's captain under communism.
The communist regime of Nicolae Ceausescu and his wife Elena was overthrown in a bloody revolt in 1989, during which the couple were shot dead.
Mr Basescu said it was vital for Romania to learn to what extent the Securitate had managed to survive and how much power it had now to influence political and economic decisions.
He said "it would have been impossible to accept the idea of Romania joining the European Union with the Securitate archives untouched".
Plea for openness
Mr Basescu vowed to publish the file on himself. "Give me this file and I will make it public straight away," he said.
Former President Emil Constantinescu and another politician, Dan Voiculescu, have accused Mr Basescu of having worked for the Securitate while he was a ship's captain.
Basescu promised a new leadership style when he won the 2004 election
Six years ago Romania set up by law a special commission, the Council for Studying Securitate Archives (CNSAS), to review the millions of secret police documents.
But it was only recently that the council started examining the past connections of prominent public figures.
Last week Mona Musca, a member of parliament and former minister of culture, confessed publicly that she had collaborated with the Securitate since the 1970s.
The media have not been spared the political scandal. A media organisation, the Civic Media Association, has called on journalists to declare publicly whether they had worked for the Securitate.
And the Romanian newspaper Adevarul reports that many sports men and women were recruited by the Securitate.
Former tennis star Ilie Nastase told Adevarul that "probably very many people co-operated".
"All those who travelled abroad must be investigated. I know a category of such Securitate officers did exist, but I have no evidence," he said.
On Basescu's orders, more than 1.3 million files have been handed over to the CNSAS since the beginning of the year.
Previous administrations had kept them secret, saying their declassification would endanger national security.
According to opinion polls, an overwhelming majority of Romanians support the opening of the archives.
Romanian analysts say information from the dossiers has been used for political blackmail during the 17 years since the Ceausescu family's fall from power.
"I believe we must see the system, because we are only just beginning to raise the curtain covering it," Mr Basescu said, urging Romanians not to get "distracted by games connected to people and party interests".