By James Pomfret CHASHAN China (Reuters) – Production has been indefinitely halted at a Chinese supplier to Samsung Electronics Co Ltd after the factory was suspected of using child workers. Samsung, the worlds biggest smartphone maker, said last week it had stopped doing business with the Dongguan Shinyang Electronics factory, a wholly owned subsidiary of South Koreas Shinyang Engineering Co Ltd, after an audit led to evidence of what Samsung called suspected child labor. The Dongguan Shinyang factory is a squat building in an industrial estate in Chashan, one of hundreds of towns spread across southern Chinas Pearl River Delta, dubbed the factory of the world. In Seoul, a senior official at parent firm Shinyang Engineering said its China factory had been idle since July 14.