TAIPEI (Taiwan News) – The Taiwan High Court sentenced retired Army Lieutenant General Kao An-kuo (高安國) to seven years and six months in prison Tuesday for promising to assist a Chinese invasion.

He was the most senior former military officer to have been involved in spying for China, per UDN. In addition to collecting secrets, Kao also planned to form a group to attack government establishments during a Chinese blockade.

Kao’s friend Liu Yi-chin (劉逸蓁) was sentenced to six years and 10 months in jail as she functioned as a contact person between his group and China. The authorities also confiscated illegal income valued at NT$4.13 million (US$134,000).

Kao’s adopted son received a six-year prison term for recruiting three members for the spy ring. The three tried but failed to expand the group, and received sentences ranging from 18 months to five years and eight months. Appeals are still possible against the verdicts.

Kao, 81, drew up plans to attack government installations if China gained control over the airspace and waters surrounding Taiwan, prosecutors said. The idea to set up an armed force to execute the plan was abandoned because of a lack of interest.

The High Court concluded that the six defendants had planned to cause chaos, intensify divisions, and damage morale. Kao had responded to calls from China based on his own political opinions, while the four recruits to his group were motivated by greed, the court said.