The chief of Taiwan's China policy-making body, the Mainland Affairs Council (MAC), resigned on Tuesday after objecting to a court ruling clearing a former deputy of leaking sensitive information to mainland China.
The former deputy, Chang Hsien-ya, had been under investigation since 2014 on allegations he had leaked information to China, but prosecutors said there was insufficient evidence of that.
The head of the council, Wang Yu-chi, submitted his resignation in response.
"I do not agree with the prosecutors' decision, but I fully respect it," Wang told a news briefing carried live on television.
The MAC said last year Chang left his post for "family reasons". Chang later said he was forced to do so.
"He was not charged due to lack of sufficient evidence in leaking information," the Taipei District Prosecutors Office said in a statement earlier.
"What Chang and other defendants had done did not damage national interests and security," it said.
The MAC handles cross-strait policy with its Chinese counterpart, China's Taiwan Affairs Office. Talks between the two have increased substantially as cross-strait business ties have surged to their most extensive in six decades.
Wang's resignation was not expected to have any impact on relations with the mainland.
