Order, denominated a judgment, Supreme Court, New York County (Martin Schoenfeld, J.), entered January 2, 1991, which, insofar as appealed from deemed plaintiff’s notice of claim and supplemental notice of claim to be timely served, and dismissed defendants’ third affirmative defense of the Statute of Limitations, unanimously affirmed, without costs.
We agree with the IAS court that defendants should be estopped from asserting the Statute of Limitations or the untimeliness of the March 12, 1990 supplemental notice of claim for wrongful death and conscious pain and suffering based upon medical malpractice because of their active concealment of plaintiff’s mother’s death, and their failure to reasonably and diligently inquire or ascertain the whereabouts of the decedent’s relatives prior to releasing the body for a funeral to the city mortuary, although a next of kin was listed (Simcuski v Saeli, 44 NY2d 442, 448; Cassidy v County of Nassau, 84 AD2d 742).
*567Nor did the IAS court err in granting plaintiff leave to serve an amended complaint setting forth more fully her allegations of fraud and concealment, where the record reveals that defendants clearly had actual knowledge of the facts underlying those claims and were therefore not substantially prejudiced by the delay in serving the notice of claim (Dodd v Warren, 110 AD2d 807; General Municipal Law § 50-e [6]). We have reviewed the defendants’ remaining claims and find them to be without merit. Concur — Murphy, P. J., Ellerin, Wallach, Asch and Rubin, JJ.