Probing lepton flavour violation in $\nu_{\mu} + N \to \tau + ...$ scattering and $\mu \to tau$ conversion on nucleons

We study lepton flavour-violating interactions which could result in the tau-lepton production in the nu(mu)N scattering or in mu --> tau conversion on nucleons at high energies. Phenomenological bounds on the strength of (τ) over bar numu(q) over barq' interactions are extracted from the combined result of the NOMAD and CHORUS experiments on searching for nu(mu) - nu(tau) oscillations. Some of these bounds supersede limits from rare decays. We also propose a "missing energy" type experiment searching for mu --> tau conversion on nucleons. The experiment can be performed at a present accelerator or at a future neutrino factory.