  The correlation function of two identical particles - pions or kaons -
interacting via Coulomb potential is computed. The particles are emitted from
an anisotropic particle's source of finite lifetime. In the case of pions, the
effect of halo is taken into account as an additional particle's source of
large spatial extension. The relativistic effects are discussed in detail. The
Bowler-Sinyukov procedure to remove the Coulomb interaction is carefully
tested. In the absence of halo the procedure is shown to work very well even
for an extremely anisotropic source. When the halo is taken into account the
free correlation function, which is extracted by means of the Bowler-Sinyukov
procedure, is distorted at small relative momenta but the source parameters are
still correctly reproduced.
