Argentina’s defense minister, Agustín Rossi, singled out a blacklist of 331 actors, musicians, writers and journalists when he announced the discovery of the documents on Monday night in Buenos Aires. The documents, which he said were found last week in the basement of the air force headquarters, largely involve detailed minutes of meetings by the dictatorship.

“We welcome this,” said Estela de Carlotto, president of the Grandmothers of the Plaza de Mayo, a human rights group that searches for children seized by the dictatorship. “It is confirmation of a repressive system, with blacklists of artists who believed in the freedom of our country.”

At one point, the list totaled 19 pages of names of artists and intellectuals deemed to have subversive leanings, including the novelist Julio Cortázar and the folk singer Mercedes Sosa. The list was drawn up by the dictatorship in an attempt to block support for such figures from state bureaucrats and private news organizations.

Investigators already knew about the persecution of cultural figures, largely through telegrams from institutions that fired them and from personal testimonies, said Valeria Barbuto, director of Memoria Abierta, which brings together human rights organizations born out of repression during the dictatorship.

“Intellectuals had told of how they were turned down for jobs or forced into exile,” Ms. Barbuto said. “But this is different. This reaffirms the truth of the victims’ stories. It shows the value of searching for documentation.”

In January 1980, nearly four years after the coup that brought the military to power, the dictatorship had 331 intellectuals blacklisted. Mr. Rossi, the defense minister, said the dictatorship classified intellectuals on a scale of F1 to F4, with the F standing for formula. An F4, for those whom the military regarded as the most threatening, meant the person had a clear “past of Marxist ideology, making advisable his non-entry into public office,” one document said, according to the newspaper Tiempo Argentino.

Notes on the lists instructed that they not be copied or their contents divulged and that they eventually be burned. By October 1982, the dictatorship was faltering and the number of blacklisted intellectuals had dropped to 153. “It is clear that as we came nearer to democracy, the lists began to be erased,” Mr. Rossi said.

Altogether, Mr. Rossi said that the files, which were discovered Thursday in two safes, two closets and a bookcase at the air force building, number about 1,500, including the minutes of the dictatorship’s 280 secret meetings from 1976 to 1983. He said 13 sets of original documents from meetings in 1976 and 1977 show how officials sought to “exhaustively monitor” a newsprint manufacturer, Papel Prensa.

A continuing criminal investigation seeks to establish whether the executives of two of Argentina’s largest newspaper companies colluded with the dictatorship in illegally forcing the family that owned Papel Prensa to sell its shares to them and to a third company in 1976. The widow of the banker who owned the company was tortured and raped in custody after she was arrested during the dictatorship.

Mr. Rossi said that it was up to Argentina’s courts to decide if the documents related to Papel Prensa had “judicial value.”

Simon Romero reported from Rio de Janeiro, and Jonathan Gilbert from Buenos Aires.