Four employees of the Taiwanese contract manufacturer that makes the Apple iPhone are in detention in China, Taiwanese authorities said Friday.

Chinese authorities are investigating four Taiwanese employees at Hon Hai Precision Industry Co., Apple Inc.’s main assembly partner, for suspected criminal activities including bribery, according to Beijing’s Taiwan Affairs Office.

Taiwan's Mainland Affairs Council, in a statement to Reuters on Thursday, said the four employees had been detained in China's Zhengzhou, home to a major Foxconn plant assembling Apple's iPhones, on suspicion of the equivalent of "breach of trust".

Chinese police have detained four workers of the Taiwanese iPhone maker, Foxconn, in circumstances Taipei has described as "strange". The employees were arrested in Zhengzhou in Henan province on "breach of trust" charges,

Four employees of Taiwan’s Foxconn, the world’s largest iPhone assembler, have been detained in China under “quite strange” circumstances, Taiwan’s government said.

Four Taiwanese employees at Chinese facilities that make products for Apple have been detained by local authorities.

The employees were detained by public security in the city of Zhengzhou for the equivalent of 'breach of trust' under Taiwan law, Taipei's top China policy body, the Mainland Affairs Council, said