  We discovered a so called high-temperature blackbody (HBB) component, found
in the 15 -- 40 keV range, in the broad-band X-ray energy spectra of black hole
(BH) candidate sources. A detailed study of this spectral feature is presented
using data from five of the Galactic BH binaries, Cyg X-1, GX 339-4, GRS
1915+105, SS 433 and V4641~Sgr in the low/hard, intermediate, high/soft and
very soft spectral states (LHS, IS, HSS and VSS, respectively) and spectral
transitions between them using {\it RXTE}, INTEGRAL and BeppoSAX data. In order
to fit the broad-band energy spectra of these sources we used an additive XSPEC
model, composed of the Comptonization component and the Gaussian line
component. In particular, we reveal that the IS spectra have the HBB component
which color temperature, kT_HBB} is in the range of 4.5 -- 5.9 keV. This HBB
feature has been detected in some spectra of these five sources only in the IS
(for the photon index Gamma>1.9) using different X-ray telescopes. We also
demonstrate that a timescale of the HBB-feature is of orders of magnitude
shorter than the timescale of the iron line and its edge. That leads us to
conclude that these spectral features are formed in geometrically different
parts of the source and which are not connected to each other. Laurent &
Titarchuk (2018) demonstrated a presence of a gravitational redshifted
annihilation line emission in a BH using the Monte-Carlo simulations and
therefore the observed HBB hump leads us to suggest this feature is a
gravitational redshifted annihilation line observed in these black holes
