  The problem of the higher-loop contributions to the axial anomaly is
reexamined by a new method. We demonstrate that these contributions depend on
the order of the calculations. If the divergence of the axial current by
nonperturbative Fujikawa method is calculated first and then average it over
the photon field in the presence of an external photon source, a nonzero
contribution is obtained. However perturbative Feynman diagram method has an
uncertainty. Depending on the order of the calculations above mentioned or zero
results are obtained.
