Nestle, the world’s largest food company, has acknowledged that it is almost certain that seafood bought from Thailand by itself and other large Western firms is produced by what are effectively modern-day slaves, many of them Cambodian.

In a report, released by Nestlé on Monday, the US-based non-profit Verité interviewed more than 100 workers in the sector, 80 per cent from Myanmar or Cambodia.

Nestlé commissioned the report after it was identified as a major buyer of Thailand’s fish products last year, and now says it will institute strict requirements for all its suppliers.

The report describes in sometimes-disturbing detail how unscrupulous brokers trick migrants into working on Thai fishing trawlers, where they face atrocious conditions and are often unpaid for more than a year.

The workers toil for hours on end with little or no medical care in filthy living conditions, staying at sea for about a month at a time, with one group of Cambodian sailors describing their lives onboard as “horrible and dangerous”.

The corpses of those who die from accidents or overwork, the report says, are simply thrown overboard.

“Sometimes, the net is too heavy and workers get pulled in to the water and just disappear,” one Burmese worker who escaped from his ship was quoted as saying.

Overall, the abuse continues due to an almost total lack of law enforcement in Thailand.

“There are no procedures to ensure that workers were brought into Thailand and to their facility through legal and humane means, or any formal due diligence processes to screen out labor broker or agent practices that could constitute trafficking or result in forced labor,” the report reads.

The report’s findings came as no surprise to Dy Thehoya, an anti-trafficking program officer at the Community Legal Education Center in Cambodia, who said the Cambodian government did little to stop the problem as well.

“People call these ‘slave ships’, and the Thai and Indonesian governments are under pressure, but that’s not the case with Cambodia,” he said.

“I do not see any action from the government.”

Thehoya said barriers to the enforcement of anti-trafficking laws include corruption and a lack of government resources, and said he was doubtful that private companies could monitor their suppliers effectively.

“How can they monitor out in the sea?”

Chou Bun Eng, chair of the National Committee on Combating Human Trafficking, said that effectively knowing the scale of the problem was difficult due to the widespread use of fake papers, admitting that too many Cambodians are “cheap and easy to exploit”.

She added that policing the border was Thailand’s responsibility as well.

“We need collaboration,” she said.