ODEMIRA, Portugal (Reuters) - Portugal is cracking down on labor trafficking, carrying out thousands of raids on farms suspected of trapping poor migrants in unpaid work, with the known number of victims almost doubling in less than a decade.

Thai workers wait for a labour conditions control at a red fruit farm near Odemira, Portugal February 7, 2019. Picture taken February 7, 2019. REUTERS/Rafael Marchante

“Labor exploitation in agricultural areas, especially in the Alentejo region, is out of control,” said Acasio Pereira, president of the inspectors’ union in Portugal’s Immigration and Border Service (SEF).

A European Commission report in December said that in 2015-16 Portugal had a higher proportion of labor trafficking victims per one million of the population than any other European Union state except Malta.

Most victims are men and predominantly from Eastern Europe as well as India, Nepal, Pakistan and Bangladesh, said SEF.

Portuguese investigators say typical victims are impoverished migrants brought to Portugal by trafficking rings with the promise of a job advertised on the Internet.

But once put to work, their identity documents are often confiscated and their pay withheld, with many packed into grim, common living quarters with few amenities.

“Human trafficking is a phenomenon that really worries us,” Filipe Moutas, a police captain in Portugal’s National Republican Guard (GNR), told Reuters as a team checked workers’ employment contracts and identity documents during a raid on a 100-acre (40-hectare) raspberry farm in Alentejo last week.

“We keep a close eye on this and regularly carry out operations of this kind. Our main concern is labor trafficking because that’s the reports we have been receiving.”

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CRACKDOWN

The Feb. 7 raid began with four police cars driving into the middle of a field where officers jumped out to locate the owner, who had Thais and Bulgarians in his workforce.

Police found no irregularities this time. All workers had the required work permits and their contracts were in order.

“I don’t recruit anyone abroad,” said the farm owner, who wished not to be named. “I need people and they just come.”

But in another raid a few weeks earlier in the nearby city of Beja, police found 26 victims of trafficking and arrested six Romanians, the biggest bust of its kind to date, the SEF said.

The Council of Europe reported last year that labor trafficking was rising across the continent and had overtaken sexual exploitation as the “predominant form of modern slavery” in several countries including Britain, Belgium and Portugal.

Portugal’s human trafficking observatory said authorities conducted 4,539 raids and inspections in 2017 at farms and other premises including shops suspected of exploiting labor. The number of known victims rose from 86 in 2010 to 175 in 2017.

The latest figures for 2018 are not yet out but Pereira said the numbers did not reflect the true scale of the scourge.

“SEF doesn’t have the capacity to inspect most properties where workers are being abused,” he said, as it had less than 20 inspectors available to probe Portugal’s interior.

Labor trafficking has risen as Portugal’s native population has aged and declined due to falling birth rates and emigration to more prosperous northern EU countries.

Another factor has been depopulation of the rural interior as young people leave for cities in search of better-paid jobs.

Meanwhile, agricultural exports have boomed in recent years and large farms need ever more cheap labor.

“The situation is worrying, particularly in sectors where there are not enough workers,” said Pereira, pointing to seasonal jobs including olive and strawberry picking.

“That’s where you find trafficking and exploitation.”