No testimony of a juvenile at a hearing pursuant to section 7 of P.L. 1982, c.77 (C.2A:4A-26) or section 8 of P.L. 1982, c.77 (C.2A:4A-27) shall be admissible for any purpose in any hearing to determine delinquency or guilt of any offense.
N.J.S. § 2A:4A-29