v. State, 259 Ga. 717 (2) (386 SE2d 316) (1989). Additionally, we have noted, albeit in dicta, that grand jurors should be impartial. [A]n injustice is done to the individual citizen when he is subjected to accusation of crime by those who would be more than normally willing to exalt bare unsupported suspicion into a reasonable ground for indictment and trial. For this reason it is proper that the court should in advance of the grand jury’s action receive information from the defendant, from an amicus curiae, or from any other legitimate source, tending to show that certain of the grand jurors would likely be biased, and that he should purge the panel, so as to make it impartial. Bitting v. State, 165 Ga. 55, 63 (2) (139 SE 877) (1927); see also Williams v. State, 69 Ga. 11 (5) (1882) (<HOLDING>), overruled in part on other grounds by Burns
recognizing that it may be appropriate in a particular case to challenge grand juror bias recognizing that implied bias is appropriate in certain situations holding that a challenge propter affectum was not a good ground for a plea to abate the accusation but noting that it is proper for the court to hear challenges to grand jurors based on bias and partiality in advance of the grand jurys action recognizing contribution in the appropriate case recognizing that although no obstruction occurs when an individual lies to fbi agents who might or might not testify before a grand jury it may occur if the agents acted as an arm of the grand jury or indeed that the grand jury had even summoned the testimony of these particular agents