Samsung Electronics has temporarily suspended business with one of its Chinese suppliers, after a labor watchdog group accused the factory of hiring five underage workers.

The South Korean company said Monday its own investigations uncovered evidence of the illegal hiring at the supplier, Dongguan Shinyang Electronics. Local Chinese authorities are also looking into the matter, it said.

“If the investigations conclude that the supplier indeed hired children illegally, Samsung will permanently halt business with the supplier,” the company said in a blog post.

New York-based China Labor Watch alleged last week in a report that the supplier had been hiring “child workers” to help assemble Samsung products.

A month ago, China Labor Watch sent an undercover investigator to examine the working conditions at the factory. Located in the Chinese city of Dongguan, the facility builds and assembles covers and components used in Samsung phones, according to the labor group.

Their investigation found that the factory had hired five workers under the legal working age of 16 to work night shifts lasting 11 hours each day. Two of those workers were 14 years old with the other three aged 15.

“Each shift is a daily struggle for these children,” China Labor Watch claimed. “Tired, they must face high quotas and strict management, with supervisors frequently yelling at them.”

The findings countered Samsung’s own recent audits, which claimed that none of its Chinese suppliers had been found hiring underage workers.

Samsung demands that all company suppliers use ID checking scanners to verify the ages of its workers. But China Labor Watch’s own investigation found that none of underage workers at Dongguan Shinyang Electronics had undergone ID checks.

In its Monday blog post, Samsung said it had last audited the factory on June 25, and found no underage workers. The company’s follow-up investigation, however, found evidence of the illegal hiring that took place on June 29.

Dongguan Shinyang Electronics did not answer phone calls on Monday. China Labor Watch said the factory had forced the five underage workers to return home, following the group’s report.