The meaning of investigation in dream | Dream Interpretation
A literal investigation will take place, formally or informally; research accordingly
If you dream about an investigation, this suggests that you are trying to solve a problem that is worrying you.
If you are the one under investigation in your dream, and you know you are innocent, you will have fortune and honor. But if you feel you are guilty, then your reputation will be in jeopardy and your friends will turn away from you.