A Chinese?assembler used by Samsung allegedly violates local labor laws by hiring underage workers and forcing employees to work excessive hours, according to the labor watchdog group China Labor Watch, which released an undercover report Tuesday, Sina.com reported.

China Labor Watch, a non-profit group that monitors working conditions in Chinese factories, sent investigators to work at the factory of Huizhou-based HEG Electronics, which makes mobile phones and DVD players for Samsung.

According to the New York-based group's undercover?investigation in June and July, seven children under the age of 16 were found working in the factory. The child laborers worked under the same harsh conditions as adults but were paid only 70 percent as much, the report said.

School-age workers comprised nearly 80 percent of the factory's workforce, the watchdog noted in its report. "In this plant the use of child labor has become a customary practice," the report said.

In addition to their routine eight-hour daily shifts, HEG employees were required to work three to five hours of overtime each day, the report added. Additionally, workers on the plant's 11-hour night shift received only one 40-minute meal break.

While HEG did not answer phone calls, Nam Ki Yung, Samsung's spokesman for southern China issued an e-mail statement saying that the company had conducted two separate on-site inspections on HEG's working conditions this year but found no irregularities on those occasions.

"In light of this report, we will conduct another field survey at the earliest possible time to ensure our previous inspections have been based on complete information and take appropriate measures to correct any problems that may have emerged," the statement said.

Li Qiang, executive director of China Labor Watch, said the group had not yet reported the case to the Public Security Bureau or other government agencies, but hopes the child laborers can return to school as soon as possible.