After installing flowmeters in the outputs of all Navy ships serviced by Fat Leonard Francis and his company, the Navy was able to compute just how much Fat Leonard was overcharging the Navy.
It appears that Fat Leonard was claiming to be sucking a lot more liquid out of the ships as the ships were even capable of carrying.
The scandal came to light when NCIS suspected one of their own agents was living a little too high for the money they were paying. An unnamed source inside one of the Navy ships in question mentioned over coffee that there were too many scantily clad women coming aboard and heading to only one or two cabins. These two things together, and the sucking charges that the ships commanders complained to the Secretary of the Navy proved to be too much for this to keep hidden for long.