  We give independent proof of the deficit of stars in the in-plane central
disc with respect to the predictions of a pure exponential density
distribution. We use three different methods: 1) the inversion of the red clump
giant distribution in near-infrared colour-magnitude diagrams to obtain the
star density along the line of sight; 2) the determination of the density
distribution of 1612 MHz sources by means of the distance determination of
OH/IR sources from their kinematical information; 3) an analysis of near and
mid-infrared star counts and comparison with models. All the tests give the
same result: a defect of stars in the inner disc with respect to an exponential
disc (either with constant scaleheight or extrapolated from the outer disc),
but only in near plane regions. This deficit might be interpreted as a flare in
the vertical distribution. The in-plane density is almost independent of R and
not an exponential law. Further away from the plane, however, the density
increases towards the centre due to the increase of the scaleheight. Tests also
show that this result cannot be due to extinction. The deficit affects both the
young and the old populations, so it is probably a rather stable feature of the
disc, and might be due to the existence of an in-plane bar sweeping the
near-plane stars.
