Order unanimously reversed, on the law, and motion granted, to the extent that the matter is remitted to Erie County Court for a hearing, in accordance with the following memorandum: The trial court erred in denying, without a hearing, defendant's motion to vacate the judgment pursuant to CPL 440.10. The direct appeal from the judgment of conviction, which was affirmed concerned only matters in the record, whereas the facts underlying the motion concerned matters outside the record. Moreover, defense counsel did not learn of these facts until after filing the brief on the direct appeal. Upon apprising this court of such facts, he was instructed to proceed with the oral argument and to present the 440.10 motion separately. Under these circumstances the trial court erred in holding that the issues presented by the instant motion should or could have been made a part of the earlier appeal ( People v Seminara, 58 A.D.2d 841). We note also that the facts underlying the motion allege that defendant's trial counsel suffered mental problems resulting in bizarre behavior not apparent on the transcript, which allegedly deprived defendant of the effective assistance of counsel. The Court of Appeals has noted that frequently a claim of ineffective assistance of counsel is not demonstrable from the record and that such an argument is better "bottomed on an evidentiary exploration by collateral or postconviction proceeding brought under CPL 440.10" ( People v. Brown, 45 N.Y.2d 852, 854). We conclude, therefore, that under the circumstances of this case a hearing is required to determine the validity of defendant's allegations ( People v. Harris, 74 A.D.2d 879, 880; People v. Seminara, supra; People v. Wedra, 56 A.D.2d 903).