650—32.9 (679) Mediation confidential. All verbal or written information relating to the subject matter of mediation or a mediation agreement transmitted between any party to a dispute and a mediator or the staff of an approved center or any other person present during any stage of mediation, whether reflected in notes, memoranda, or other work products in the case files, is confidential communications except as otherwise expressly provided for in Iowa Code chapter 679. Mediators and center staff members shall not be examined in any judicial or administrative proceeding regarding confidential communications and are not subject to judicial or administrative process requiring the disclosures of confidential communications. This rule does not apply when a mediator or center staff member has reason to believe that a party to a dispute has given perjured evidence.