A Taiwan court convicted and jailed a retired vice admiral for 14 months on Monday for spying on behalf of China, the court said.
Taiwan has been hit by a string of spying scandals in recent years, reflecting the fact that intelligence gathering has continued despite warming ties with Beijing.
Ke Cheng-sheng, 70, was found guilty of collecting confidential Taiwanese military information and helping China develop an espionage network on the island, the district court in the southern city of Kaohsiung said in a statement.
He had already retired when he carried out the acts.
Taiwanese merchant Shen Ping-kang was jailed for one year on the same charges, the court said, adding both can appeal.
Taiwan and China have spied on each other ever since they split in 1949 at the end of a civil war. Beijing still regards the island as part of its territory awaiting reunification, by force if necessary.