Is it illegal to hire a private investigator? The straight answer to that question is NO, it’s not illegal.
You or anyone can hire a private investigator and it's as legal as you would hire a lawyer.
But the question regarding legalities raises other questions that need to be addressed. The questions are not so much about the legal hiring of a private investigator in itself, but the activities that are undertaken once you have hired one.
Yes, it is legal to employ the services of a private investigator, but why you want to hire one and how the investigation is conducted will decide whether or not there are illegalities involved.
Any private investigator or private detective with a moral compass will not engage in illegal investigations. They will tell you straight if what you are asking them to do is illegal; and if serious may consider informing the authorities.
However, if your request does cross the fine line and tips the balance slightly, a trained investigator can sometimes use his or her experience and knowledge to find an alternative legal solution... Read the full article here.