Air France-KLM Royal Dutch Airlines have confirmed they are under investigation regarding contracts with the United States Postal Service (USPS) for the international transportation of mail by air. The civil inquiry was reported in the airlines' latest annual report, which came out on April 3.

The Franco-Dutch carrier said it was informed of the inquiry in March 2016 by the United States Department of Justice (DOJ), which is investigating potential violations of the False Claims Act. In September 2016, the DOJ sent the airlines a Civil Information Demand seeking information into their contracts with USPS.

The False Claims Act relates to entities which attempt to defraud US governmental programs by making false claims for payment or approval.

Air France and KLM have stated that they are cooperating with the DOJ in the investigation. The DOJ did not respond to a request for comment into the case.