does private investigator need power of attorney to recover unclaimed funds

Typically, a private investigator should not require a power of attorney to assist you in processing an unclaimed funds case.   I would be wary of giving anyone a power of attorney unless you know them personally.  Depending on the powers designated in the power of attorney, they will essentially be “you” and allowed to access bank accounts, transfer real estate, etc…   In unclaimed funds’ cases, it is very possible that an administrative hearing will be required.  This means that ultimately you will have to hire an attorney and will have spent money and time on investigator.   If you do not have the funds to hire an attorney, there are many attorneys will consider taking your case on a contingency fee basis.