The CBI, which is probing the sensational murder, has petitioned the Metropolitan Magistrate's court for Mukerjea's voice sample.
The central probe agency had told the court yesterday that it had got hold of some call recordings which purportedly featured her voice, and therefore it wanted her voice sample for verification.
All three accused in the case--Mukerjea, her ex-husband Sanjeev Khanna and former driver Shyamvar Rai--are in judicial custody in the case.