"Today, Patel retracted from his earlier statements," Ashwini Sharma, assistant public prosecutor, told reporters.
The earlier statements were recorded before a judicial magistrate to ensure that there is no pressure from the investigating agency.
But now, the witness turned hostile saying that he gave the earlier statement under pressure from National Investigation Agency (NIA), which had charged right wing extremists including some RSS members for the blast which killed three and injured 15 people in 2007.
Several other witnesses have also turned hostile in the case.