The Commissioner shall have power to investigate upon complaint of any interested person or upon his own initiative the record of any applicant, licensee or unlicensed person, partnership or corporation alleged or suspected to be a dealer in agricultural products, or any transaction involving the solicitation, receipt, sale or attempted sale of agricultural products, the failure to make proper and true accounts and settlements at prompt and regular intervals, the making of false statements as to condition, quality or quantity of goods received or while in storage, the making of false statements as to market conditions with intent to deceive, or the failure to make payment for goods received, or other alleged injurious transactions. For such purposes the Commissioner or his agents may examine, at the place or places of business of the applicant or licensee, his ledgers, books of accounts, memoranda, and other documents which relate to the transaction involved, and may take testimony under oath.