Eight months after the murder of teenager Aarushi Talwar and her family's domestic help, a Central Bureau of Investigation (CBI) official admitted on Friday they have no 'clinching evidence' and that the case against the three accused is weak.

"We have completed our investigations and will be filing our chargesheet very soon. Though we cannot give any time-frame, more likely it will be done within two-three weeks," a CBI officer said on condition of anonymity. "Our chargesheet will be based on forensic evidence."