sentences:  During the trial, the defence argued that the proceedings were invalid as Knight had been granted immunity by the Attorney-General's Chambers in 1991 from further charges arising from his corruption investigations, in exchange for him to plead guilty in the earlier trial.They argued that the latest set of charges stemmed from that investigation and thus were subject to the immunity clause.The CPIB revealed that it had been tipped off about the misappropriation of money only in 1997 by an unnamed informant.