  A novel theory of radiative electron capture in second forbidden non-unique
transition, is applied to reanalyze experimental data obtained previously for
the decay of 59Ni. The measured gamma spectrum is shown to be distorted at the
high-energy end, presenting the first direct evidence for the virtual
beta-gamma transition through the excited state in 59Co. The complete
theoretical predictions, including both the direct and the virtual decay
channels, as well as the interference between them, reproduce very well the
experimental spectrum. The virtual nuclear component amounts to about 4% of the
total gamma intensity.
