Apple Inc is once again in a whirlwind of labor rights abuse accusations by a key supplier in China as a New York-based advocacy group has made fresh allegations following an undercover investigation of three mainland factories of Taiwan-based Pegatron Corp.

The labor rights watchdog China Labor Watch claimed in a report on Monday that it has found at least 86 labor rights violations at three Pegatron factories in Shanghai and neighboring Suzhou.

Li Qiang, executive director of China Labor Watch, said the organization sent a team of investigators from March to July to work in the factories and interviewed about 200 workers outside the factories where 70,000 people make iPhones, Mac computers and iPad parts.

The violations investigators found included asking workers to work for 66- to 69-hour weeks, beyond the legally required 49 hour maximum without overtime.

Pegatron was also accused of using underage workers under the name of interns who worked the same long hours. The organization also claimed a pregnant woman was required to conduct the same workload as other co-workers.

In an Apple statement on Monday, the electronics giant said it had communications with China Labor Watch in the past months and investigated the issues it raised and took action, including requiring Pegatron to return the withheld IDs.

"Their latest report contains claims that are new to us and we will investigate them immediately. Our audit teams will return to Pegatron, RiTeng and AVY for special inspections this week," said the Cupertino, California-based company.

It said if the workers are found to be underpaid or denied compensation, it will ask Pegatron to reimburse in full.

Pegatron President and CEO Jason Cheng said in a statement that his company will investigate the accusations. Charles Lin, its chief financial officer, was quoted by Bloomberg News as saying Pegatron has not hired any underage workers in China and workers averaged 45- to 50-hour weeks over the previous two to three months.

Apple, which outsources all its production to mainland factories owned by Taiwan electronics manufacturers including Foxconn and Pegatron to lower manufacturing costs, has been at the center of labor rights disputes and a favorite target of labor rights groups.

In 2010, 14 workers committed or tried to commit suicide at several Foxconn factories in China in less than 10 months, which led to a large-scale investigation by Apple, Foxconn and Chinese authorities and contributed to the improvement of workers' working and living conditions at Foxconn factories.

Since then, the American giant has reinforced audits on social responsibility compliance of its manufacturers and worked out a code of conduct.

Kenneth L. Kraemer, a professor at UC-Irvine, said accusations like this could hurt sales of Apple products in China, which is Apple's second-largest and fastest-growing market in the world.

"But I do not know whether the people who actually buy the products care about these issues. I also do not know whether Chinese consumers consider CLW to be an objective (non-political) source of information," said Kraemer.

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