The Taipei District Prosecutor's Office then opened its own investigation. It collected evidence from the Ministry of Finance, the Bank of Taiwan, Chung Hsing Bills Finance, and other institutions. After tracing the flow of money, it then called in Chen Pi-yun and Soong Chen-yuan for questioning.
台北地檢署亦隨即展開偵辦「興票案」，向財政部、台銀、興票等單位調閱帳、證資料，並將在釐清資金流向之後，傳喚陳碧雲、宋鎮遠等人到案說明。