The director, without previous notice, shall visit the office of an alien bank doing business in this state pursuant to this chapter at least once every eighteen months, and more often if necessary, for the purpose of making a full investigation into the condition of such office, and for that purpose they are hereby empowered to administer oaths and to examine under oath any director or member of its governing body, officer, employee, or agent of such alien bank or office. The director shall make such other full or partial examination as he or she deems necessary. The director shall collect, from each alien bank for each examination of the conditions of its office in this state, the estimated actual cost of such examination.