In a letter to the Union Home Minister, Badal said, "Despite best efforts, the state police department has failed to make any breakthrough in the case."
"Since the matter is of very urgent and sensitive nature so I reiterate my request to you for looking into the case personally and issue necessary orders to entrust investigation of this case to CBI for quick dispensation of justice to the aggrieved family," Badal wrote.
The Punjab government had earlier urged the MHA to hand over the investigation of the case to the CBI, but no response was received from the Centre, said an official release.