105 ILCS 5/33-5: Interest in contracts or transactions.

No member or employee of the board shall be directly or indirectly interested in any contract, work, or business of the district, or in the sale of any article, the expense, price or consideration of which is paid by the district; nor in the purchase of any real estate or property belonging to the district, or which shall be sold by virtue of legal process at the suit of the district. Whoever violates any provision of this Section shall be guilty of a Class A misdemeanor.