Polish authorities arrested a sales director of Huawei Technologies Co. and charged him with conducting espionage on behalf of China, raising the stakes over Western allegations the global company is a spying tool for Beijing.

The Chinese national’s detention follows the December arrest of Huawei’s chief financial officer in Canada, at the U.S.’s request, on allegations the company violated U.S. sanctions on Iran. Unlike that case, the Polish charges relate directly to suspicions by Washington and other Western governments...