Three gangmasters supplying workers to an Evesham-based vegetable packer have had their licences revoked after an unannounced raid found unsafe working practices were putting migrant workers lives at risk.

The raid, just before Christmas at the Simms and Wood warehouse at Wyre Piddle, was carried out by the Gangmasters' Licensing Authority (GLA) as part of its Operation Scorpion, assisted by West Mercia Police and the Border and Immigration Agency.

Simms and Wood packs onions for Sainsbury's Asda, Morrisons, Iceland, Lidl and Aldi, the GLA said.

As a result of evidence uncovered during the raid, Birmingham-based gangmaster A to Z Employment Services had its licence revoked with immediate effect.

The main reasons were that an unlicensed, unroadworthy minibus was used to transport workers, and the agency boss had told a worker to put clingfilm on a serious cut and carry on working on a food production line.

Two other gangmasters had their licences revoked "without immediate effect", allowing them to continue trading until the appeals process has been exhausted.

"The GLA is determined to root out worker exploitation," said GLA chairman Paul Whitehouse. "We can not allow an agency that puts its workers at risk to continue trading."

The GLA said other serious issues uncovered included the manipulation of documents, specifically passports, by a labour provider and a lack of accurate records of the number or identity of workers employed at the warehouse.

Employees were also found to be working 60 to 70 hours a week, with only 39 hours shown on their payslips.

The GLA is expected to carry out further enforcement operations throughout the UK to root out illegal working practices. This follows the GLA's first annual performance review in December, which recommended more inspections and urged the GLA to call for more intelligence from labour providers and users.