  We consider the supersymmetric seesaw mechanism induced by the exchange of
heavy SU(2)_W triplet states, rather than `right-handed' neutrino singlets, to
generate neutrino masses. We show that in this scenario the neutrino flavour
structure tested at low-energy in the atmospheric and solar neutrino
experiments is directly inherited from the neutrino Yukawa couplings to the
triplets. This allows us to predict the ratio of the tau --> mu gamma (or tau
--> e gamma) and mu --> e gamma decay rates in terms of the low-energy neutrino
parameters. Moreover, once the model is embedded in a grand unified model,
quark-flavour violation can be linked to lepton-flavour violation.
