Taiwan's mainland affairs chief Wang Yu-chi announced his resignation on Tuesday, taking responsibility for forcing his former deputy to quit in August last year over allegations that he had leaked official secrets.

At a press conference announcing his decision, Wang said he felt sorry for the social turmoil caused by the case involving former mainland affairs deputy chief Chang Hsien-yao.

Wang's resignation came shortly after Taipei prosecutors said earlier Tuesday that they would not indict Chang for allegedly leaking secrets to the Chinese mainland because of a lack of evidence.

Expressing his disappointment, Wang said he cannot agree with the prosecutors' view but has no choice but to respect it.