We study the impact of a type-I SUSY seesaw concerning lepton flavour violation (LFV) at low-energies and at the LHC. At the LHC, $ \chi_2^0\to \tilde \ell \,\ell \to \ell \,\ell\,\chi_1^0$ decays, in combination with other observables, render feasible the reconstruction of the masses of the intermediate sleptons, and hence the study of $\ell_i - \ell_j$ mass differences. If interpreted as being due to the violation of lepton flavour, high-energy observables, such as large slepton mass splittings and flavour violating neutralino and slepton decays, are expected to be accompanied by low-energy manifestations of LFV such as radiative and three-body lepton decays. We discuss how to devise strategies based in the interplay of slepton mass splittings as might be observed at the LHC and low-energy LFV observables to derive important information on the underlying mechanism of LFV.