  From an analysis of the ionisation energy loss of charged particles selected
from 110326 e+e- -> tau+tau- candidates recorded by the OPAL detector at e+e-
centre-of-mass energies near the Z0 resonance, we determine the one-prong tau
decay branching ratios:
  Br(tau- -> nu_tau K- >=0h0) = 1.528 +- 0.039 +- 0.040 %
  Br(tau- -> nu_tau K-) = 0.658 +- 0.024 +- 0.029 % where the h0 notation
refers to a pi0, an eta, a K^0_S, or a K^0_L, and where the first uncertainty
is statistical and the second is systematic.
