When a motion is based on facts not appearing of record the presiding officer may hear the matter on affidavits presented by the respective parties, but the presiding officer may direct that the matter be heard, wholly or partly on oral testimony.
Ga. Comp. R. & Regs. R. 360-22-.02
O.C.G.A. Secs. 43-1-3, 43-34-24(c).