  The central region of the barred spiral galaxy M83 reveals a polar-nucleus
dust lane, wh ich extends from the NE molecular bar and crosses the central
bulge. Its SW counterpart is not visible, being hidden behind the bulge. This
asymmetry, in spite of the galaxy's face-on orientation and the symmetric bar
struct ure in the CO-line emission, indicates that the dark lane is an
off-plane structure. Such a ``polar-nucleus'' structure can be formed by a
non-coplanar, three-dimensional acc retion in a warped disk.
