Justice R.Mala gave the direction on a petition by R Seenichamy, a retired government officer, who sought a CBI probe into the case.
Refusing to transfer the case to CBI, the judge directed that it be investigated by a new DSP (Investigating Officer).
The petitioner alleged that police and the magistrate helped the accused, who 'attacked him, on the instructions of state Finance Minister O Panneerselvam.
According to the petitioner, State Bank of India's Kanniappapillai Patti branch Field Officer Boologa Sundar attacked him when he went to the bank on July 21.