A US judge has thrown out a $2.3m (£1.5m) award won by six Nicaraguans against Dole Food Company, ruling that the firm was the victim of fraud.
In 2007, a jury found in favour of the men who said they had been left sterile by exposure to pesticides while working on Dole banana plantations.
But Judge Victoria Chaney said that fraud by the plaintiffs' lawyers had left Dole unable to defend itself.
One lawyer had recruited bogus banana workers for the case, she said.
The original trial centred around the use of pesticides - namely dibromochloropropane or DCBP, which was banned in the US but was used on Dole plantations in Central America in the 1970s.
The initial verdict was hailed as a landmark decision that could possibly open the case for thousands of other workers to seek compensation.
The latest ruling now casts doubt over these cases, correspondents say.
Judge Chaney, sitting in the Los Angeles Superior Court, ruled on Thursday that "there was massive fraud perpetrated on this court".
"The plaintiffs have unabashedly tampered with witnesses," she said, adding that it may never be known who worked on the banana plantations and were harmed by pesticides.
Judge Chaney said that Los Angeles lawyer Juan Dominguez recruited people to say they had been banana workers, coaching them in what to say during the trial.
"It has effectively destroyed any Nicaraguan's ability to seek compensation in (US) court," Steve Condie, a lawyer for the six Nicaraguans, told Reuters, adding that they would appeal.
Another lawyer for the men, Antonio Hernandez Ordenana, said the ruling was "immoral".
He also said that "nobody proved in court that the six workers were not banana employees".
Lawyers for Dole argued that the conspiracy was prompted by a law passed in 2001 in Nicaragua to address the issue of pesticide exposure.
The case had been brought by fake banana workers, Dole lawyer Scott Edelman said.
"The few remaining banana workers who believe they were harmed ware hurt by the conduct of people who bring false claims," he said.