A police sergeant has been suspended from duty because he failed to investigate two foreigners who it turned out were driving without licences in Minato ward, Tokyo. The policeman explained that the two men didn't understand Japanese and he decided it would be too much trouble to call for an interpreter. It has come to light because it appears that the policeman did issue a traffic ticket while ignoring the licensing problem.
Story here (Japanese)
EDIT:Other media reports say that the two foreigners were riding motorcycles while only having car driving licences which makes it a little clearer.