Buried damaged layers in n-silicon created by implantation of MeV heavy ions has been studied by capacitance-voltage (C-V), current-voltage (I-V) and deep level transient spectroscopy (DLTS) techniques. In samples irradiated with doses below amorphization threshold, besides divacancy related trap, a new midgap acceptor trap level is isolated and shown to be responsible for carrier compensation. This defect level controls hysteresis in C-V characteristics and space charge limited current conduction in I-V characteristics. Possible origin of this defect have been discussed in the light of defect migration and cluster formation.