Whenever it appears, after investigation by the comptroller or otherwise, that there exists or may exist escheated property under this article, the attorney general may take action to recover such property. For such purpose the attorney general may institute special proceedings in the name of the people of the state of New York in the supreme court of this state. In any such proceeding there shall be named as respondents

1. (a) All last known owners or claimants appearing in the records of the United States. These may be described as a class when

   1. (i) they own or claim property of the same nature and the value of such property as shown on the account of each such owner or claimant in the records of the United States does not exceed five hundred dollars in value, or
   2. (ii) the records of the United States show more than ten such owners or claimants for a particular fund, item or category of property, or
   3. (iii) the records of the United States fail to disclose the number of owners or claimants for a particular fund, item or category of property with a reasonable degree of certainty.
2. (b) All unknown owners or claimants. These may be described as a class.