Inquisitor (noun)

A person who conducts an inquiry or investigation, especially an official investigation into a crime or other alleged wrongdoing.

Origin:

Inquisitor is derived from the latin word "inquisitor" meaning one who inquires, examines or investigates.

Examples:

1. The inquisitor was appointed by the king to investigate the alleged corruption in the royal court.
2. During the inquisition, inquisitors were appointed to investigate and prosecute heretics.
3. The police detective acted as an inquisitor, questioning the suspects in the case.
4. The inquisitor asked many questions to the accused to find out the truth.
5. The inquisitor was trying to find out more about the company's illegal activities.