  We present optical and infrared spectra as well as the proper motion of an
H=12 mag object 2" off the ~5 mag brighter spectroscopic binary star CoD-33
7795 (=TWA-5), a member of the TW Hya association of T Tauri stars at ~55 pc.
It was suggested as companion candidate by Lowrance et al. (1999) and Webb et
al. (1999), but neither a spectrum nor the proper motion of the faint object
were available before. Our spectra taken with FORS2 and ISAAC at the ESO-VLT
reveal that the companion candidate has spectral type M8.5 to M9. It shows
strong H-alpha emission and weak Na I absorption, both indicative of a young
age. The faint object is clearly detected and resolved in our optical and
infrared images, with a FWHM of 0.18" in the FORS2 image. The faint object's
proper motion, based on two year epoch difference, is consistent with the
proper motion of CoD-33 7795 by 5 Gaussian sigma significance. From three
different theoretical pre-main sequence models, we estimate the companion mass
to be between ~15 and 40 M_jup, assuming the distance and age of the primary. A
slight offset between the VLT and HST images with an epoch difference of two
years can be interpreted as orbital motion. The probability for chance
alignment of such a late-type object that close to CoD-33 7795 with the correct
proper motion is below 7e-9. Hence, the faint object is physically associated
with CoD-33 7795, the 4th brown dwarf companion around a normal star confirmed
by both spectrum and proper motion, the first around a pre-main sequence star.
