I work in the contracting field, and merchants bring me projects from the government. Is it permissible for me to ask them whether they paid a bribe?

Question:
Honorable Shaykh, may Allah grant you success. He says: I work in the field of contracting and construction, and sometimes I take on an architectural project from some merchants who obtain it from the government. Must I ask these merchants how they obtained this project? Did they pay a bribe or not? My work is with both them and the government.

Answer:
The default for a Muslim is trust. As long as nothing has become apparent to you, do not investigate hidden matters. The default for a Muslim is trust; hold a good opinion of the Muslim.