The group said that seven workers under the age of 16 years old were found working at a factory owned by HEG Electronics, in the city of Huizhou, Guangdong province, between June and July. The plant makes phones and DVD players for Samsung.

A cause of the problem, according to the group, is that younger students mixed with older students working during school holidays. HEG Electronics had limited supervision mechanisms. Student employees work under the same conditions as adult workers, but receive 70 percent of wages that other workers do. Overtime of 3-5 hours a day is compulsory and is added on top of an 8 hour day.

The report was filed by an undercover investigator who worked for a two month period, as well as two interviewers who worked outside the factory.

Samsung told several media sources, including the Washington Post, that previous inspections of HEG Electronics by the company did not reveal any violations. The company will send a team to investigate allegations today.