The two men from Taiwan's outlying Kinmen island were found on March 18 by the coastguard of China's Fujian province after the engine of their boat failed.

One of the anglers, identified only by family name Hu, is an active member of Taiwan's military, state news agency Xinhua reported on Friday, citing a spokesman of the Taiwan Affairs Office -- a Chinese body that handles cross-strait affairs.

"He did not truthfully provide his identity and fabricated false professional information to intentionally conceal it," spokesman Chen Binhua said.

"Relevant (mainland) departments need to further verify and understand the situation."

The other man -- surnamed Wu -- will be repatriated to Kinmen on Friday, Chen said, without providing more information.

Taiwanese officials had urged Beijing to quickly repatriate the duo, though they did not confirm if one of them was in the military.

The incident comes during an ongoing row between Taipei and Beijing over a fatal boat incident last month.

A Chinese speedboat carrying four people capsized on February 14 near Kinmen while being pursued by the Taiwanese coast guard, killing two people while the other two survived.

Beijing has accused Taipei of "hiding the truth" about the incident, while the Taiwanese coast guard said the boat involved had entered "prohibited waters", was zigzagging and "lost its balance" before capsizing.

China said it will step up patrols around Kinmen following a series of deadly incidents, including the sinking of another boat in the area this month that resulted in the deaths of two crew members.

China claims self-ruled Taiwan as part of its territory, and has said it will not rule out force to bring the island under Beijing's control.