In general parlance if a defence witness turns hostile during the examination in chief if the evidence is not given by way of evidence on affidavit....the hostile witness is subject to further cross examination by the defence counsel to test the veracity or impeach the deposition of the said witness by virtue of sectio 138 of the Evidence Act, however if a witness turns hostile during the re-examination can be he be impeached and subjected to cross examination though the order may be broken as laid down under section 137 of the Evidence Act....??? Can such impeachment be conducted suo moto by the Presiding Sessions Judge or is it at the instance of the counsel conducting the Examination or taking evidence....???