香港政府部門通常會唔會主動去查案的？定係百分百靠人舉報？田?

The HKSAR Government does not usually have the authority to investigate unless a complaint is filed.

However, there is also an exception - if you have to transact with an agency of the HKSAR Government, then that agency can act accordingly.

For example:

1. The IRD can audit and investigate based on the tax returns filed.

2. Social Welfare Department can conduct aduit and investigation of CSSA abuse even without complaints.

3. The Housing Department can investigate public housing abuses and audit residents.