PARIS (AFP) - Two workers for delivery company FedEx traveled from Paris to Vienna in a cargo plane after apparently dozing off, a company source said Saturday.

The two men were working early Friday at Charles de Gaulle airport. They are believed to have fallen asleep while waiting for a freight delivery that didn't arrive, the source said on condition of anonymity.

The doors for the plane's freight compartment were closed without anyone noticing they were there, the source said.

So off they went to Austria. The two workers were returned to France later in the day aboard an Air France flight. The company has opened an internal investigation to determine what happened.

"There is some doubt as to whether they were really sleeping," a FedEx spokesperson told AFP. "All we know is that they were repatriated and they are safe and sound."

Copyright 2007 Agence France Presse.