24/7 Wall St.

French officials revealed on Tuesday that $2 million in gold bars disappeared from an Air France passenger plane after the gold had been loaded on the plane for a flight to Zurich. The gold bars weighing approximately 161 pounds appear to have been stolen before the plane left Paris on a flight for Zurich operated by Air France budget carrier Hop!.

U.S. security firm The Brink’s Co. (NYSE: BCO) said it delivered the gold to the plane and that “the parcels weren’t under [Brink’s] responsibility when they disappeared.” Investigators have not ruled out the possibility that the gold disappeared once the plane landed in Zurich.

Last June a plane from Switzerland to New York with a delivery of cash for the U.S. Federal Reserve Bank of New York arrived with $1.2 million missing from a scheduled delivery of $93 million.

Air France has claimed it was the victim of the gold theft and has filed a complaint with French authorities, according to The Wall Street Journal. An airlines spokesman said the gold shipments are insured but gave no additional details.