Fox News reports that the US Transportation Security Administration (TSA) stopped the company from handling cargo at the Indianapolis facility after initial findings in late December.
Interviews with employees at the facility reportedly indicated that they were complying with direct orders from their supervisors to forego the screening process in order to save money.
The civil action has now turned into a criminal investigation and according to reports, the TSA has brought in criminal investigators to interview OHL and Activair employees both past and present.
The TSA has also sent agents to Activair's Chicago, Seattle and New York facilities. In response, OHL International has voluntarily suspended Activair's operations across the US.
In a statement to FOX59 News, OHL spokesperson Kara Brown said: "OHL International has suspended the US air export business of Activair.
OHL will continue to ship cargo from the US via air through its Barthco International subsidiary, a TSA-authorized indirect air carrier. Activair is continuing to fully cooperate with the inquiry by the TSA."
OHL, a large third-party logistics firm headquartered in Tennessee, specialises in shipping for the publishing industry.
The news will surely be a major concern to the US Homeland Security Secretary Janet Napolitano, who just days ago announced that governments must work closer to improve security within international air cargo.
As previously reported, parcel bombs sent from Yemen and destined for the US were discovered in October, prompting the TSA to introduce tougher security measures for the screening process.
The investigation also comes less than a month after the Global Air Cargo Advisory Group (GACAG) called for a serious enhancement in security measures in all aspects of the air cargo supply chain.