A United States district court has dismissed a case against two Thai and two American companies filed by seven Cambodians allegedly trafficked and forced to work on fishing boats.

Central District Court of California Judge John F Walter ruled on Thursday to toss out the case, with his earlier arguments contending that there was not enough evidence of a connection between companies in the US and the alleged trafficking.

The complaint was filed in June 2016 and alleges the seven Cambodians – two women and five men – were lured to Thailand under false promises and held in extreme working conditions for Thai Phatthana Seafood company in 2011 and 2012. The firm exports to the US.

The complaint details the workers’ arduous migration to Thailand, in which they were allegedly “packed like sardines in a pick-up truck” and continually threatened with violence. After arriving, the complaint alleged, conditions remained dire, with workers facing food shortages.

“[S]ome workers could not afford to purchase enough food and were constantly hungry. For example, Plaintiffs Ban and Nakry looked for food growing in nearby fields and found snails and fish washed up on the shore in order to eat,” it continues.

When workers tried to leave, they were allegedly told they couldn’t get their confiscated passports back until they had paid off exorbitant recruitment fees, out of reach given their salaries were well below what they were allegedly promised.

The complaint contended that US companies Rubicon Resources, and Wales & Co Universe – along with Thai companies Phatthana Seafood and SS Frozen Food – were responsible for peonage, forced labour, involuntary servitude and human trafficking, as they were “participants in a joint venture that in violation of US law knowingly profited from the import and sale of shrimp and seafood produced with trafficked labor”.

In the December 21 minutes preceding the judgment, Judge Walter argued there wasn’t sufficient proof to establish a connection between the US firms and trafficking to warrant the court’s jurisdiction over the case.

The complaint also implicates Cambodian recruitment agency CDM Trading Manpower in arranging the migration and extorting workers. Lim Vouchna, an officer of the company, said CDM Trading Manpower no longer worked with Phatthana.

Dy The Hoya, of labour rights organisation Central, said judicial processes were “very complicated” for victims of human trafficking and that companies often won court cases due to inequality of resources. “It’s not fair for the workers,” he said.