N.Y. Suffolk County Tax Act § 40-e
The county treasurer is hereby authorized and empowered and shall, upon the application of any one whomsoever aggrieved thereby, set aside any cancellation of sale made by him or by any of his predecessors in office, in any of the following cases:
First. When such cancellation was procured by fraud or misrepresentation.
Second. When it was procured by the suppression of any material fact bearing on the case.
Third. When it was made under a mistake of fact.
Fourth. When such cancellation was made upon an application which the county treasurer or any of his predecessors in office had no jurisdiction or legal right to entertain at the time of such cancellation.
Eight days written notice of an application made under and pursuant to this section shall be served upon the person upon whose application such sale was cancelled, or his heirs or grantees, the county treasurer, and the county attorney; in case any of the parties to be served are not residents of the state of New York, or cannot after reasonable diligence be found within the state of New York, such notice may be served by the publication thereof in the two newspapers designated under this article for the publication of the advertisement of notice of sale of unpaid taxes, once in each week for three weeks immediately preceding the day upon which such application is to be made, and also by mailing a copy of said notice to each of said parties at his last known place of residence; and on or before the day of the first publication all papers upon which such application is to be made shall be filed with the county treasurer. The county treasurer shall in all cases specify the grounds upon which such cancellation is set aside, and every such cancellation set aside by the county treasurer shall in every and all respects have the same force and effect as though no cancellation thereof had ever been made.
N.Y. Suffolk County Tax Act § 40-e