Chung Ting-pang is suspected of having got hold of several classified documents from residents in the Chinese mainland since 2003, according to a state security organ in east China's Jiangxi province.
He is also thought to have sent broadcasting and television devices to the mainland and suborned mainland residents to sabotage broadcasting and TV facilities, state- run Xinhua news agency reported.
Chung colluded with others several times to use professional devices to disturb satellite signals which were used to relay mainland TV programs to Taiwan, Jiangxi's state security organ said.
"Chung's behaviour has violated China's relevant criminal laws, and he is suspected of conducting criminal activities that are detrimental to national and public security," said a statement from the body.
Jiangxi officials summoned Chung orally to ask him to assist investigation of the cases on June 18.
To meet the requirements of the investigation, the security organ decided later at night to exercise compulsory monitoring of Chung's residence, the report said.
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On June 19, the security organ notified a relative of Chung in the mainland of his situation and arranged for the relative to meet him in the afternoon.
It also asked the relative to tell Chung's wife, who is in Taiwan, that he is assisting with the investigation.
Jiangxi's state security organ conducted Chung's case in accordance with the laws and has safeguarded his rights during the procedure, the statement said.