Workers in the southern California garment industry are being robbed of millions of dollars a year in unpaid wages thanks to labour violations by their employers, says the US Labor Department.

The department’s Wage and Hour Division conducted 221 investigations of employers in fiscal 2014, almost all in and around Los Angeles, and found just over US$3m in unpaid wages for 1,549 workers.

This amounted to an average of $1,900 per worker, five times the average weekly wage of a typical sewing machine operator.

“Fierce competition in the garment industry leads many contract shops to lower the cost of their services, frequently at the expense of workers’ wages,” said Dr David Weil, administrator at the Wage and Hour Division.

“When workers don’t receive the wages to which they are legally entitled, they can’t afford the basics like food, rent and child care.”

The division has responded by engaging in “strategic enforcement efforts”, including directed investigations and identifying supply chains to combat what Dr Weil called a “race-to-the-bottom culture”.