  The occurrence of a significant amount of supersymmetric lepton flavour
violation at laboratory energies, through $\tilde\nu_\mu - \tilde\nu_\tau$
mixing, has become a realistic possibility in the wake of the super-Kamiokande
atmospheric neutrino result. This effect can be observed in an e+e- linear
collider with the distinct final state tau+mu+ jets+E_T. We show that the pair
production of charginos can make an important contribution to this process and
has to be taken into account in addition to that of sneutrinos or charged
sleptons. Some case studies are presented with CM energies of 500 and 800 GeV
and integrated luminosities of 50, 500 and 1000 fb-1.
