State attorneys are looking into whether he had sex with an inmate in exchange for a razor.
Justin Husom resigned after the allegations surfaced.
The story came to light when deputies said an inmate bragged about the consensual sex.
Deputies said Husom tried to throw investigators off the trail.
Sheriff Richard Lathim said "The first person that brought it to our attention was actually the officer involved. He said that there was rumors among the inmates that he had done something inappropriate and he just wanted to let us know that it was not true."
The Franklin County Prosecutor tells KEPR the complaint was turned over to the Attorney General's Office.
Shawn Sant said it would be a conflict of interest for the county to handle the case of an employee.