OPINION OF THE COURT
Memorandum.
The order of the Appellate Division should be reversed, and the case remitted to that court for further consideration in accordance with this memorandum.
One of the substantive issues tendered for consideration on this appeal is whether it was proper to permit the prosecutor on cross-examination to impeach an eyewitness to defendant’s arrest, called by the defense, for failure to report to law enforcement authorities or the office of the District Attorney exculpatory information to which he testified on trial. The Appellate Division held that the issue had been preserved for appellate review and that such cross-examination was "unfair and improper” and "impinged upon defendant’s right to a fair trial”, mandating a new trial (65 AD2d 405).
Our examination of the record discloses that defendant did *786not register a timely or effective protest to the challenged cross-examination and therefore failed to preserve the error, if any, for appellate review. After the prosecutor, without objection, had asked some 19 questions relevant to the failure of the witness to come forward, when he asked the twentieth, capping question defense counsel interposed an unembellished "objection” which was overruled. We conclude there was no timely objection to this line of cross-examination and note that when objection was finally made defense counsel did not advance the theory of error which he now asserts (22 NYCRR 604.1 [d] [4]).
In this procedural posture, the case must be remitted to the Appellate Division for that court to determine whether to exercise its discretionary power to review defendant’s claim of reversible error in the absence of adequate protest and, if it so determines, then to rule thereon (People v Cona, 49 NY2d 26, 33-34). We do not reach or consider other assertions of error advanced by defendant.
Chief Judge Cooke and Judges Jasen, Gabrielli, Jones, Wachtler, Fuchsberg and Meyer concur.
Order reversed and the case remitted to the Appellate Division, First Department, for further proceedings in accordance with the memorandum herein.