For the purpose of ascertaining the corporate net worth tax imposed by this article, the net worth of the corporation shall be presumed to be the net worth as disclosed on the corporation's books and as reflected on the return required to be filed annually by the corporation. In the event the commissioner ascertains that the books of any corporation reporting under this article or the return filed for any corporation reporting under this article, as provided in Code Section 48-13-77, does not disclose the true net worth of the corporation, the net worth of the corporation shall have the value fixed by the commissioner from any information obtained by the commissioner from any source.