Wis. Stat. § 16.975: Access to information.

The department shall withhold from access under s. 19.35 (1) all information submitted to the department by agencies, authorities, units of the federal government, local governmental units, entities in the private sector, or individuals for the purpose of processing. The department may not process such information without the consent of the agency, authority, unit, entity, or individual which submitted the information and may not withhold such information from the agency, authority, unit, entity, or individual or from any other person authorized by the agency, authority, unit, entity, or individual to have access to the information. The agency, authority, unit, entity, or individual submitting the information remains the custodian of the information while it is in the custody of the department and access to such information by that agency, authority, unit, entity, or individual or any other person shall be determined by that agency, authority, unit, entity, or individual and in accordance with law.