French-Bulgarian philosopher Julia Kristeva briefly collaborated with Bulgaria's communist-era secret services, but was of limited use to them, according to archive material published on Friday.
Kristeva has lived in France since 1966 and has written extensively on psychoanalysis and literary theory.
Allegations that she collaborated with Bulgaria's intelligence agencies first emerged earlier this week.
She denied the claims in a statement on her website, calling them "grotesque and false" and threatened legal action against media outlets repeating them.
A Bulgarian commission charged with opening up the country's secret communist-era archives published more than 160 pages of documents about Kristeva on Friday.
The files mostly contain details about Kristeva's academic and political activities, but also include some of the information she allegedly provided to agents -- and that her codename was Sabina.
"Towards the end of 1970 she began to give information about our nationals abroad, about progressive Arab organisations, especially Palestinian ones, and the activities of Maoist groups," said an intelligence report dated November 10, 1984.
"The information she provided is not particularly interesting and she lacks discipline: claiming that she was busy, she would forget meetings or fail to attend them," the report said.
After Kristeva adopted Maoist ideas "she was definitively shut out from the apparatus of collaboration at the beginning of 1973," the report continued.
Koprinka Chervenkova, a former anti-communist dissident, defended Kristeva on Friday.
"Mundane interviews with Julia Kristeva are being interpreted as being agent reports. But the documents published reveal her personal strategy was to protect her family (from persecution)," Chervenkova said.