Every person shall make and retain such accounts, records, and memoranda necessary to fully and correctly disclose all transactions involved in the person’s business, including the true ownership of such business by stockholding or otherwise. Whenever the commissioner finds that the accounts, records, and memoranda of any such person do not fully and correctly disclose all transactions involved in the person’s business, the commissioner may prescribe the manner or form and length of time for retention which such accounts, records, and memoranda shall be kept. The commissioner shall at all reasonable times have access to, for the purpose of examination, and the right to copy any documentary evidence of any person being investigated or proceeded against.