(1) The department's investigation shall be conducted in a prompt and impartial manner. The department shall normally utilize methods such as written information requests and telephone interviews to obtain information in the course of the investigation, relying upon more formal investigative tools such as subpoenas and depositions only after attempts to achieve voluntary cooperation have been unsuccessful.

(2) The department, in investigating a charge of discrimination under the act, may exercise any and all of the powers of the commission provided for in 49-2-203 , MCA. These include the power to subpoena witnesses, take the testimony of any person under oath, administer oaths, and require the production for examination of tangible evidence, such as documents, relating to the case. In exercising its powers, the department may issue subpoenas, take depositions, serve interrogatories, and require the production and disclosure of any tangible evidence.

(3) The powers of the department to conduct investigations are continuing from the time that a complaint is filed until the case is resolved, or a hearing on the complaint is held. The department may exercise its investigative powers in determining if a conciliation agreement is being honored or an order of the commission, issued after hearing, obeyed.