Relatives of Kuo Yu-hsuansaid he had notified them of his safe arrival in the Chinese city on Aug. 27, but nothing had been heard from him since. Kuo planned to travel onward to Hefei in the province of Anhui, reported Taiwan News.

Relatives failed to contact him and posted a message online to report the man as missing.

A sister told Taiwan News that they feared he had been forced into work by a fraud ring, or had been abducted.

SEF has notified its Chinese counterpart, the Association for Relations Across the Taiwan Straits (ARATS), about Kuo’s case, but has not received a reply, the news portal reported.