I've actually come across this by accident and checked it a few times to make sure that it wasn't some random out-of-the-blue glitch. What I did is I got the nazi's attention but kept the alarm at level 1 (haven't tried higher) and made them follow me to the rebel hideout at the slaughterhouse (cant remember the name) and then ran to the door to go into the hideout and tried getting in 3 times then ran over to the guy who controls the garage and bam, you got your 99,999 contraband.