Apple Valley's fire chief resigned last month after being investigated over an "inappropriate relationship" he had with a city employee.
A statement issued by the city confirmed that Nealon Thompson resigned from his position as of Oct. 24, saying he "didn't want his actions to reflect negatively" on the department.
The city had launched an investigation in late April, after Thompson told City Administrator Tom Lawell he had "recently engaged in unprofessional conduct."
That conduct, the Pioneer Press reports, was a sexual relationship with another city employee, which the city considered to be inappropriate for a department head.
The newspaper notes that Thompson became a paid firefighter in August 1991 and took over as the city's fire chief in September 2008.
He was placed on administrative leave for a period of time in April while the city attorney's office investigated his conduct.
This investigation concluded that Thompson's actions could result in disciplinary action, with the fire chief deciding to resign as a result.
Deputy Chief Chuck Russell has been appointed the acting fire chief until a permanent replacement is found.