The gross proceeds of any lottery, less the amount awarded in prizes and any salary, fee, or commission paid to a licensed lottery operator plus any interest on such funds, shall be segregated from any other revenue and placed in a separate account of the lottery operator and the county, city, or village. If a lottery operator is conducting a lottery on behalf of a county, city, or village, such proceeds, including any interest, shall be transferred from the lottery operator's separate account to a separate account of the county, city, or village. Any interest received by a county, city, or village from the proceeds of the lottery shall be used solely for community betterment purposes. Separate records shall be maintained by such licensed county, city, or village. Records required by the Nebraska County and City Lottery Act shall be preserved for at least three years unless otherwise provided by rules and regulations adopted and promulgated by the department. Any law enforcement agency or other agency of government shall have the authority to investigate the records relating to lotteries and gross proceeds from such lottery at any time. Any county, city, or village shall, upon proper written request, deliver all such records to the department or other law enforcement agency for investigation.