Where's the Congressional investigation?
The Republicans in Congress probably had access to this knowledge, but refused to act because they were 'playing nice' with the Dem'crats, as a conciliatory move toward the Dem'crats. Should the Dem'crats ever get in a postion of power, went the reasoning, Dem'crats would then reciprocate by not looking too closely at what the Republicans may have done on their watch.
Dem'crats play along in part. Now that they are in charge, this particular series of incidents will be swept entirely under the rug, clearing the field for fresh indictments of Republican malfeasance to be put under close examination.