An undercover investigator, undercover detective, or undercover agent can be a person who conducts investigations of suspected or confirmed criminal action even though impersonating a disinterested third party. Sherlock Holmes, the world's most popular fictional private investigator A private investigator (frequently abbreviated to PI and informally known as a private https://www.owss.eu/rd.asp?link=https%3A%2F%2Fwww.ntetektib-athina.gr%2F