By LARRY ROHTER
 
RIO DE JANEIRO, Jan. 30 - As if by magic, incriminating documents supposedly incinerated years ago by the government have suddenly reappeared. As a result, Brazil is being forced to confront one of the most distasteful aspects of its past: the death, disappearance or torture of hundreds of political prisoners during 21 years of military dictatorship.

For years, the military and state intelligence agencies swore that no records of that dark era still existed. "They were all legally destroyed in the 80's and 90's, in accordance with established procedures," José Viegas said in an interview late in 2003 when he was the civilian minister of defense, citing assurances he said he had received from the military high command.

But in October, a pair of photographs said to be those of Vladimir Herzog, a political prisoner killed in 1975, unexpectedly resurfaced. In the outcry that followed, the former military intelligence agent who supplied the pictures said they were among thousands of pages of documents supposedly destroyed after democracy was restored in 1985 but were in fact in secret archives still out of the reach of civilian authorities.

Reluctantly, the state intelligence agency and the intelligence branches of the armed forces admitted the claim was true. Since then, President Luiz Inácio Lula da Silva, a former labor leader who was himself briefly jailed by the dictatorship, has been grappling with the problem of what to do with the documents and how to punish senior intelligence and military officials, some still in government service, who lied about the records' destruction.

In files that have already been opened, some shocking discoveries have been made. João Luiz Pinaud, director of the government's Special Commission on the Death and Disappearance of Political Prisoners until late last year - when he resigned, complaining of a lack of official support - said he had opened one crate of papers and found with them almost an entire skeleton, apparently of a guerrilla killed more than 30 years ago in the Amazon.

"Not only were documents concealed, illegally destroyed and lied about, but bodies were hidden, cemeteries were vandalized and witnesses were coerced, all of which are crimes," said Mr. Pinaud, a former judge and now a law professor. "My question is what, if anything, the government intends to do about it."

Initially, the army sought to justify its mistreatment of political prisoners, leading to a confrontation with Mr. Viegas. Mr. Viegas stepped down in November after Mr. da Silva declined to fire or even publicly rebuke the army commander, Gen. Francisco de Albuquerque, for what political commentators here described as a lack of discipline and a breach of the principle of civilian supremacy.

Recognizing the seriousness of the situation, Mr. da Silva then appointed his vice president, José Alencar, as the new defense minister. After a lunch last month with commanders of the three military services, which coincided with the first meeting of a new government commission asked to decide what to do with the trove of documents from the dictatorship, Mr. da Silva praised "the loyalty, dedication and patriotism of the armed forces."

Nonetheless, last month a cache of partly burned documents, some of them dated as late as a decade after the return to civilian rule, was uncovered at an air force base in the northeast. Other deposits of papers have been found at a school in the northeast and on a ranch in the far southern part of the country.

The number of people who died, disappeared or were tortured during the military dictatorship that seized power in 1964 is significantly smaller than the thousands who perished in smaller neighboring countries. But until the recent revelations forced his hand, Mr. da Silva was much less energetic than Néstor Kirchner of Argentina or Ricardo Lagos of Chile in pressing for those responsible to be brought to justice.

The military seized power here a decade earlier than in those other countries, so "we exported our torture know-how to our neighbors and really invented all these terrible things like the disappeared," said Cecília Coimbra, a leader of the human rights group Torture Never Again. "But when it comes to recuperating our historical memory, Brazil has lagged behind because our governments, this one included, have never taken a tough stance."

Among those who have expressed reservations about making the documents public is Mr. da Silva's own national security chief, Gen. Jorge Armando Félix. In an interview published in November by Folha de São Paulo, he said that "some dossiers worry us, because they deal with people in extremely embarrassing situations."

Some former guerrillas were having affairs that their spouses do not know about even today, he said, while other former prisoners had informed on their comrades, sometimes without being tortured. "Nobody should know about this except with the authorization of the person involved," General Félix contended.

In some quarters, that has been interpreted as a warning to the current left-leaning government to back off. "General Félix made a threat, that if you insist on this, we will reveal things that you won't like," Mr. Pinaud said.

But now that the existence of the files has been confirmed, Mr. da Silva is facing pressure to make them available. Nilmário Miranda, the government's human rights secretary, did not respond to requests for an interview, but other officials have proposed sending everything to the National Archives, where, Mr. Alencar suggested, "serious" historians and other researchers would be allowed to see at least some of the papers.

But that does not satisfy human rights groups, which vow to step up their campaign when normal business here resumes after Carnival next month. They want to achieve what they call the "complete, unrestricted and immediate" opening of all files and to establish museums and cultural centers where Brazilians can have access to a shameful chapter in their country's history.

"It's not only relatives of the dead and disappeared who want to know where, how and when their loved ones were killed," Ms. Coimbra said. "These were acts of violence committed against all of society, and the state has to assume its responsibility, not try to block or limit the dissemination of these documents."