Samsung Electronics Co., the world's largest smartphone maker, said it suspended a supplier in China after finding evidence of illegal hiring.

The supplier will be permanently cut from Samsung's business if it's found to have hired underage workers, the Suwon, South Korea-based company said in a statement.

China Labor Watch, a worker activist group, last week said at least five workers below the legal age of 16 worked at the plant in Dongguan, amid increased scrutiny of practices in the supply chains of technology companies.

The supplier was subject to an audit in March 2013, followed by inspections in August and on June 25 this year, with no child labor found, the company added.

"Samsung will strengthen its hiring process not only at its production facilities but also at its suppliers to prevent such cases from reoccurring," officials said.