Act Governing Relations with Hong Kong and Macau Article 34

The Central Bank of China may regulate, restrict or prohibit the inflow and outflow of Hong Kong or Macau capital to and from the Taiwan Area when necessary to maintain the stability of financial or foreign exchange markets. The regulations for this shall be formulated by the Central Bank of China together with relevant agencies and submitted to the Executive Yuan for approval and subsequent promulgation.
中文原文 香港澳門關係條例第34條
香港或澳門資金之進出臺灣地區,於維持金融市場或外匯市場穩定之必要時,得訂定辦法管理、限制或禁止之;其辦法由中央銀行會同其他有關機關擬訂,報請行政院核定後發布之。

English translation for reference only; the Chinese text prevails. Not legal advice.