(a) Except in accordance with a proper judicial order or as otherwise provided by law, it is unlawful for any of the following to divulge or make known in any manner the amount of income or any particulars set forth or disclosed in any report filed under article 9-A:

(b) The words except in accordance with a proper judicial order or as otherwise provided by law means that a disclosure is permitted solely for tax purposes in appropriate proceedings where the integrity of the report itself is attacked or defended as the main issue, and not merely as a collateral issue.

(c) The officers charged with the custody of reports are not required to produce any of them or evidence of anything contained in them in any action or proceeding in any court, except on behalf of the State of New York or the Tax Commission in an action or proceeding under the provisions of the Tax Law or in any other action or proceeding involving the collection of a tax due under the Tax Law to which the State of New York or the Tax Commission is a party or a claimant, or on behalf of any party to any action or proceeding under the provisions of article 9-A when the reports or facts shown thereby are directly involved in such action or proceeding, in either of which events the court may require the production of, and may admit in evidence, so much of said reports or of the facts shown thereby as are pertinent to the action or proceeding and no more.