During Luiz Inбcio Lula da Silva's successful presidential campaign in 2002, his Workers' Party received up to $3 million in illegal campaign contributions from the government of Cuba.
The report, which the party and the Cuban government have denied, has reignited the wide-ranging corruption scandal that has paralyzed da Silva's government for nearly six months.
After a month of muted complaints that conveyed a sense that the worst was over, opposition leaders have reacted to the report with threats of a new, politically exhausting investigation and even impeachment proceedings.
"This is a serious occurrence in every respect," Senator Tasso Jereisatti, a leader of the center-left Brazilian Social Democratic Party, said in an interview with the newspaper O Estado de Sгo Paulo, noting that Brazilian law forbids campaign donations from foreign sources. "If it is proven, the president is going to have no alternative. He will not have the conditions to be able to govern; he'll have to give up his job."
The report, in the magazine Veja, did not say how the money, said to be cash in American dollars, was transported from Cuba to Brazil.
But it quotes two party functionaries, both former aides to Antфnio Palocci, then a senior member of Mr. da Silva's campaign team and now the finance minister, as saying the money was delivered by a Cuban diplomat, hidden in cases of Johnny Walker whiskey and flown to Mr. da Silva's campaign headquarters.
Da Silva, who has maintained all along that he was unaware that a multimillion-dollar slush fund was being used to buy the support of members of Congress and to pay his media adviser's bills off the books, has not yet commented directly on the accusation. But the president of the Workers' Party, Ricardo Berzoini, dismissed the Veja report as false and politically motivated.
The government of Cuba, which funneled money to selected guerrilla groups and left-wing parties in Latin America through the 1980's but says it has abandoned the practice because of its own moribund economy, also denied the report in emphatic terms.
Relations between President Fidel Castro of Cuba and da Silva and the Workers' Party have always been cordial. During Brazil's era of right-wing dictatorship, Josй Dirceu de Oliveira e Silva, the president of the party during the 2002 campaign, was exiled for several years in Cuba.
The corruption scandal, the worst in modern Brazilian history, has left da Silva, who ran on a good government platform and will be up for re-election in less than a year, on the defensive, The New York Times reports.