Reviews of payments showed inconsistencies that led back to one consultant, several former employees and one unknown party, the company said.
However, the investigation showed that the alleged theft had not directly affected clients.
The company said suspicion is centering upon an outside consultant based in southern Europe who allegedly falsified expenses and manipulated bills to enrich himself.
A Munich Re spokeswoman on Friday noted that the missing funds were discovered after an internal investigation and were reported by the company itself.