40 ILCS 5/5-216
Except as may be otherwise provided herein, no annuity, pension or other benefit shall be paid to a policeman or widow, based upon any salary paid by virtue of a temporary appointment; and no disability benefit shall be paid for any period during which he is receiving wages or compensation from any statutory body supported in whole or in part by taxation; and no annuity shall be paid to any policeman or widow who has received a refund of salary deductions or other contributions unless such amount so refunded shall have been repaid into the fund in accordance with this Article.
No annuity shall be paid pursuant to Sections 5-127, 5-145, or 5-162 of this Article, or service credit allowed for any annuity or disability benefit purposes for any period of time (except as provided in Section 5-213 of this Article) for which a policeman has not contributed to this fund or to any police pension fund superseded by this fund, through salary deductions or otherwise, unless he or his widow or both, have paid into this fund within one year from July 1, 1929, or within one year from the date of any re-entrance or reinstatement in the service subsequent to July 1, 1929, the amounts he would have contributed to this fund or to any such superseded police pension fund (had deduction been made from his full salary as such policeman during every period of service for which he has not in fact contributed), together with interest at 4% per year on such amounts from the dates upon which they respectively become due, until the date such amounts have been paid. If such payment be not made in full within the time specified herein, the board shall, at the expiration of such time, refund to the policeman or to his widow, and if there is no widow then in accordance with Section 5-167 of this Article, any partial payment which has been made, together with interest of 4% per year to the date of expiration of the period during which payment should have been made.
40 ILCS 5/5-216