TAIPEI (Taiwan News) – The Ministry of National Defense has found 62 military staffers holding Chinese residence permits, though none of them had obtained Chinese passports, Defense Minister Wellington Koo (顧立雄) said Wednesday.

The findings were the result of a probe until March 20 covering volunteers, conscripts serving their one-year military service, and reservists called up for four months, the Liberty Times reported. Only two of the 62 military staffers were volunteers, while the conscripts were still required to serve as long as they held Taiwan passports, the minister said.

So far, none of the officers were found to hold longer-term residence documents such as IDs or passports in China, Koo told lawmakers. The probe followed the discovery in February of a Navy officer whose mother had obtained a Chinese ID for him without his knowledge. He was later allowed to keep his Taiwan nationality.

Koo said holders of Chinese residency documents are not allowed to serve in sensitive departments of the military. He named intelligence gathering, communications, Air Force flights, Navy ships, research and development, and new weapons as off-limits. They would also not be allowed to serve as aides to senior officers, he said.