35 ILCS 200/20-35
The county collector shall, as provided in Section 2 of the Public Funds Investment Act, invest and reinvest the proceeds of the lesser of any taxes paid under protest or funds withheld from distribution and held in a Protest Fund, as provided in Section 23-20. The investments shall be obligations of the United States Government maturing not more than 91 days after the date of purchase, or savings accounts, including certificates of deposit, investment certificates or time deposit open accounts, in banks or savings and loan associations insured by the United States or other federal agency. Investments made in obligations of the United States Government shall be at then existing market price and in any event not to exceed par plus accrued interest. The cost price of the obligations and all savings accounts in banks or savings and loan associations shall be considered as cash in the custody of the county collector. All earnings accruing on any Protest Fund investment or bank or savings and loan association savings account in excess of those amounts paid as interest on moneys refunded to taxpayers shall be credited to and paid into the county corporate fund, except as provided in Section 23-20.
No bank or savings and loan association shall receive public funds under this Section unless it has complied with Section 6 of the Public Funds Investment Act.
After the effective date of this amendatory Act of 1997, no additional funds shall be deposited into a Protest Fund, other than interest on investments of funds that were deposited into a Protest Fund prior to this amendatory Act of 1997.
35 ILCS 200/20-35