Migrant workers in Boston say they are being abused and exploited.
The claim comes after the town's Citizens Advice Bureau (CAB) said it had received a flood of complaints.
Attention has focused on migrant workers being ripped off by unscrupulous gangmasters since the death of 19 Chinese cocklers.
The CAB in Boston says some workers are not being looked after properly by their employers and are often unaware of their rights.
Alison Fairman, from the CAB, said: "When you have migrant workers who are working for gangmasters the health and safety issues are not explained.