Derek Wilkinson, director of Sandfields Farms in Stratford-upon-Avon and Worcestershire, has spoken of his regret after discovering modern-day slaves were given work at his premises, according to the BBC, with two of the victims employed through a licensed recruitment agency.

"I regret that we've ended up with victims in our business and if we'd picked it up we would have been able to help them. "It has been horrific, and I'm really pleased the police have got the prosecution through," Mr Wilkinson said.

In July, eight people were sentenced to between three and 11 years for trafficking, conspiracy to require another to perform forced labour and money laundering. .

The farmworker victims had been recruited by gang member Julianna Chodakowicz, who had taken on a role at agency E-Response Recruitment, regulated by the Gangmasters and Labour Abuse Authority (GLAA).

Paul Alekna, of Workforce Staffing, formally E-Response, said hidden exploitation was a serious problem for unskilled labour employers and said he was pleased the firm helped identify victims.

Ian Waterfield, from the GLAA, said: "Even now it's not always possible for the employer, including those who have GLAA licences, to identify those under the control of others."