A gangmaster who supplied migrant workers to harvest leeks sold at Sainsbury's has lost his licence after being found guilty of abuse...An investigation by the Gangmaster Licensing Authority found that about 50 Polish and Slovakian workers at ELS Recruitment Ltd…had been threatened, verbally abused…and had been sacked for questioning their treatment. One worker had allegedly been assaulted by Shamus Paul, the company's director…Paul supplied his workers to Allpress Farms…[T]he farm director...[said] "I was very disappointed - this shouldn't be allowed to continue…" Allpress Farms supplied its leeks to Produce World…which in turn sells the vegetables to Sainsbury's...Produce World said the company subjected all labour agencies it used to "stringent audits"…Judith Batchelor, of Sainsbury's, said…"Sainsbury's takes the welfare of workers and sourcing with integrity very seriously and this is the type of behaviour that both we and Produce World find totally unacceptable." Paul and ELS could not be reached for comment…