Multiple sources familiar with the investigation into last year's traffic jams near the George Washington Bridge tell NBC 4 New York at least half a dozen potential federal indictments in connection with the scandal may be handed down as early as January.

Those facing potential indictment include former staffers to Gov. Christie and current and former Port Authority officials, the sources said. Possible charges may be related to what sources familiar with the probe describe to NBC 4 New York as an apparent conspiracy to cover up what they refer to as a politically motivated plot.

NBC 4 New York learned of the potential development in the investigation a day after a 136-page interim report by a joint legislative panel tasked with investigating the lane closures found no evidence Christie was involved in the scheme. The report obtained by news organizations Thursday night echoed the findings of an independent investigation commissioned by Christie's administration that found no proof the governor was involved in the closures or subsequent cover-up.

Christie attorney Randy Mastro applauded the report's findings in a statement Thursday, saying it found "there is not a shred of evidence Governor Christie knew anything about the GWB lane realignment beforehand or that any current member of his staff was involved in that decision."

The Port Authority declined to comment.

The report leaked Thursday night noted some gaps in information, however. It said several critical witnesses have not testified and that important questions remain unanswered. The report will be supplemented if more information is obtained.

The lawyer for the special joint legislative committee, Reid Schar, found no conclusive evidence that Christie was aware of the lane closures, but he said two former Christie aides, in concert with a former Port Authority appointee, acted with "perceived impunity" and with little regard for public safety when they ordered the lanes closed.

Some committee members told NBC 4 New York they felt it was clear Christie misrepresented what he knew and when he knew it, while others refuted that contention entirely, saying there was no indication the governor was involved. Most appear to agree there was poor judgment, but say whether that constitutes a criminal offense can only be determined by the U.S. Attorney's office.

The U.S. Attorney's office's investigation is ongoing, though sources tell NBC 4 New York it's likely to wrap up within the next month and a half. The office does not comment on ongoing investigations.

The joint legislative panel's interim report, meanwhile, is set to be officially released Monday.

