The Files Commission's archives don't contain an explicit, written agreement from Bozhan Stoyanov, deputy minister in charge of the energy sector in Bulgaria's caretaker government, to become collaborator of the former Communist State Security.

The statement was made by caretaker Prime Minister, Marin Raykov, on the heels of the surprising claims about Bozhanov, reported one day earlier.

Speaking at an emergency briefing Thursday, Raykov said the archives did not include even a single trace of the alleged collaboration.

The Files Commission, a panel investigating the Communist era records, announced Wednesday that in 1988 Stoyanov has been recruited under the alias Mladenov on grounds of documents they found about his lead officer and a personal file.

Bulgaria's Minister of Economy, Energy and Tourism Asen Vasilev was quick to send a letter to the commission's head, asking for clarification.

"A 2008 probe of the Files Commission concluded there was no evidence Mr Stoyanov was a collaborator of the communist secret police," the letter claims.

A member of the Commission has told the Bulgarian online news agency Dnevnik the above has been valid 5 years ago, but at the time they were unable to check the archives in the way they have done it now.

Raykov reiterated Thursday the probe in 2008 had not discovered any traces of Stoyanov's involvement with the State Security, and he has been currently singled out due to just one, suddenly emerging recruiting card.

"Nothing has changed in his past since 2008. I invited the media with some embarrassment as after the fall of Communism the issue with State Security turned into the chalga of the transition period. I voiced full support for the Files Commission, but we should stick more to our conclusions and not offer grounds for speculations. The State Security background checks cannot be used as a form of racket to destabilize the administration and be updated every six months. The members of my Cabinet do not need temporary indulgencies," the caretaker PM stressed.

He explained he could change his opinion on the issue if authentic and strong evidence emerges.

Stoaynov, himself, told the media that his role was to work to restructure the energy sector.

"When I was invited for the post, I was questioned on my past and I gave an answer," he said.