The guys holding the guns are in a foul mood. Bad enough that they have to stand out here beneath the fierce ­Colombian sun—90 degrees and spiking on a July morning—guarding a banana farm. But here comes this ­foreigner in a taxi with a camera and tape recorder, asking about death squads and massacred workers. Sweaty fingers drum against warm steel.

To talk to strangers in Urabá, an alluvial plain of former jungle thick with ­bananas and paramilitary hit men, is to ask for trouble. For more than 40 years, a civil conflict has ravaged Colombia, pitting Marxist rebels against the army and its proxy right-wing militias. In the past ­decade alone, the paramilitary group United Self-Defense Forces of Colombia, or A.U.C., has committed an estimated 62 massacres in the region of Urabá, killing 3,778 people and forcing 60,000 peasants off their land. It’s little wonder that no one wants to open his mouth.

In fact, the whole town is on edge. Two nights earlier, Marxist guerrillas ambushed two police officers at a roadside checkpoint, killing one. Everyone expects the paramilitaries to seek revenge. My driver, a man with friends on the farm, barks a rapid greeting at the guards. They peer into the car, eyeing me with disdain. The driver drops a name and the guards confer, then reluctantly wave us in.

It was here, in northern Colombia’s lush banana-growing region, that Chiquita Brands International, the $655 million fruit giant, slipped into a blood-soaked scandal. Between 1997 and 2004, Chiquita gave $1.7 million to the A.U.C., whose death squads destroyed unions, terrorized workers, and killed thousands of civilians. Chiquita’s top officials ­admit approving the payments but say they thought that if they didn’t pay up, the A.U.C. would kill its employees and attack its facilities. Because the U.S. State Department has labeled the A.U.C. a terrorist organization, federal prosecutors charged Chiquita in March with engaging in transactions with terrorists. In an agreement with the Justice Department, Chiquita pleaded guilty and will pay a $25 million fine.

But the company’s troubles haven’t ended there. The Justice Department has been investigating the half-dozen executives who approved the payments and is weighing the possibility of charging them as individuals. At press time, Chiquita lawyers expected prosecutors to present their findings to a federal judge by September 17, when the company was to be formally sentenced.

Among those being investigated are former Chiquita chief executive Cyrus Freidheim Jr. (now C.E.O. of Sun-Times Media Group) and former Securities and Exchange Commission chairman Roderick Hills, who served on Chiquita’s board and is married to Carla Hills, who served as the United States trade representative under President George H.W. Bush. (Freidheim and Hills declined to discuss the case.) In addition, Colombia’s attorney general, Mario Iguarán, has vowed to extradite Chiquita officials who authorized the payments to face charges in Colombia. “This was a criminal relationship,” Iguarán has said, that led to “the bloody pacification of Urabá.”

Chiquita also faces three civil suits that have been filed in U.S. courts. Terry Collingsworth, general counsel for the Washington-based International Rights Advocates, has filed the largest, on behalf of the families of 174 A.U.C. victims. Collingsworth, who forced oil giant Unocal into a reported $30 million settlement in a case regarding human-rights abuse in Burma in 2004, says, “I would be delighted to get a punitive-damage award that would put Chiquita out of business.”

Chiquita “categorically denies the allegations” made in the lawsuits, says a spokesman. “We will not allow ourselves to become extortion victims in the United States. We will defend any preposterous suit of this nature vigorously.”

In Colombia, multinational companies’ ties with the A.U.C. are part of an ongoing investigation that is gripping that country as intensely as Watergate did the U.S. The links between ­Colombia’s political and military elite and the paramilitary group have so far led to the arrest of more than a dozen current and former Colombian congressmen—and now those connections are threatening to bring down the government of President Alvaro Uribe, the United States’ closest ally in South America.