Appeal by defendant from a judgment of the Supreme Court, Kings County (Kreindler, J.), rendered April 20, 1978, convicting him of murder in the second degree, upon a jury verdict, and imposing sentence. Judgment-reversed, on the law, and new trial ordered. Although the evidence indicative of consciousness of guilt which surfaced during the presentation of defendant’s alibi defense may well have been sufficient to corroborate the accomplice testimony relied upon by the People (see CPL 60.22; see, also, People v Kirkpatrick, 32 NY2d 17, 21; People v Cona, 60 AD2d 318, 326, mod 49 NY2d 26; People v Ruberto, 10 NY2d 428; People v Leyra, 1 NY2d 199, 208; People v Pignataro, 263 NY 229, 234; People v Deitsch, 237 NY 300, 303), we must nevertheless reverse, as we cannot agree with the People’s contention that the conceded error in permitting the prosecution to improperly impeach one of its own witnesses (Roland Smith) in purported compliance with CPL 60.35 (see People v Fitzpatrick, 40 NY2d 44) was harmless under the facts of the instant case. This “impeachment” evidence was the only independent evidence adduced by the People tending to connect the defendant with the commission of the underlying crimes, and thus was a principal source of evidence upon which the jury may have relied to supply the requisite corroboration. The very real prospect of such improper reliance mandates a new trial herein. Damiani, J. P., Mangana, Rabin and Gulotta, JJ., concur.