Section 24C. The department shall investigate all complaints of discrimination, and for that purpose the commissioner or his authorized representative shall have full power and authority (1) to investigate and ascertain the age of each person employed within the commonwealth and (2) to enter any place of business or employment, other than places of employment of persons engaged in domestic service in the home of the employer, within the commonwealth for the purpose of examination and making a transcript of records in any way appertaining to or having a bearing upon the question of the age of any person so employed.