The mainland is called "goodbye police"
It was sung by Feng Cuihua.
The tune of this song is based on a Catholic religious song in Europe. The lyrics of the female voice are in Italian, and the content is "Goodbye, Police", but it doesn't have the lyrics from Infernal Affairs. Just humming
What is written on the soundtrack cd of Hong Kong?
Episode "Goodbye" lead singer/Feng Cuihua @ Click Music
Choir: chan kwong wing, Feng Cuihua, Lai and Asia Philharmonic Choir.
Recorder/Heron Tong @ Click Music/Zeng Jingxiang @MBS
Studio/Beijing Film Studio/Click Music Studio
Year: 2003