  We report the first detection of a hard power-law tail in the X-ray spectrum
of the black hole candidate (BHC) binary X1755-338, which was observed in 1989
March-September during the TTM Galactic Centre survey. In addition, an
ultrasoft thermal component with a temperature of ~1.1-1.4 keV was also
detected. We demonstrate that the soft and hard X-ray components of X1755-338
vary independently, as in the spectra of the well known BHCs LMC X-1, LMC X-3
and GX339-4 in their high (intensity) state. If the hard tail observed from
X1755-338 is generated near the black hole by energetic electrons up-scattering
low energy photons, the un-correlated variations imply that the soft X-rays
from accretion disc may not be the main photon seeds needed for inverse
Comptonization. The TTM observations strongly suggest that X1755-338 does
indeed belong to the family of BHCs.
