If either the prosecution or the defendant subsequently learns of additional material or information which it would have been under a duty to disclose pursuant to any provisions of this article had it known of it at the time of a previous discovery obligation or discovery order, it shall expeditiously notify the other party and disclose the additional material and information as required for initial discovery under this article. This section also requires expeditious disclosure by the prosecution of material or information that became relevant to the case or discoverable based on reciprocal discovery received from the defendant pursuant to subdivision four of section 245.20 of this article.
New York Legal Code