The use of an informant to conduct a search (such as looking around a private back room of a business) is illegal. Any evidence obtained would be thrown out of court. Similarly, the evidence from the "sneak and peek" (illegal entry w/o a warrant) would be similarly inadmissible.
Additionally, an agent involved in a relationship with an informant's attorney would not be allowed to work the case.
Additionally, an agent involved in a relationship with an informant's attorney would not be allowed to work the case.