Many of those workers were student interns, but even discounting that, temporary workers still made up to 30 percent of the workforce. Apple confirmed to Bloomberg that "the percentage of dispatch workers exceeded our standards," adding that it's "working closely with Foxconn to resolve this issue." Foxconn also affirmed that it was violating laws by hiring too many temporary workers.

Dispatch workers hired by third party firms can make higher base wages than full-time hires, but don't receive benefits like paid sick leave, vacations, medical benefits, unemployment insurance and pension contributions, according to CLW.

The organization also found a number of other violations, saying that resignations often weren't approved during peak periods, student interns were working overtime during peak production in violation of laws, workers were putting in up to 100 hours of overtime per month (36 is the maximum allowed) and that some workers never received promised overtime bonuses. However, Apple denied many of the claims.

"Most of the allegations are false," the company said. "We have confirmed all workers are being compensated appropriately, including any overtime wages and bonuses, all overtime work was voluntary and there was no evidence of forced labor." Apple added that less than one percent of its workforce was student workers, and that only a small percentage had worked overtime in violation of laws. Those issues have now been corrected, it said.

Apple's latest iPhone XS smartphones are reportedly more complex to produce than the iPhone X, requiring more workers. Apple and Foxconn aim to produce around 12,000 devices per shift, according to CLW. Recently, Amazon also admitted to hiring more temporary workers than allowed following another investigation by the labor rights group.