  We report the results of a search for the decay modes B0 -> J/psi D0bar and
B+ -> J/psi D0bar pi+. The analysis is based on 140 $\rm fb^{-1}$ of data
accumulated by the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$
collider. No significant signals are observed and we determine the branching
fraction upper limits B(B0 -> J/psi D0bar) < 2.0 10^{-5} and B(B+ -> J/psi
D0bar pi+) < 2.5 10^{-5} at 90% confidence level. These results rule out the
explanation of the excess in the low momentum region of the inclusive J/psi
spectrum as intrinsic charm content in the B meson. The branching fractions of
the corresponding non-resonant decay channels are also reported.
