  A search for second and third generation scalar and vector leptoquarks
produced in ep collisions via the lepton flavour violating processes ep -> mu X
and ep -> tau X is performed by the H1 experiment at HERA. The full H1 ep data
sample taken at a centre-of-mass energy of 319 GeV is used for the analysis. No
evidence for the production of such leptoquarks is observed in the H1 data.
Leptoquarks produced in ep collisions with a coupling strength of 0.3 and
decaying with the same coupling strength to a muon-quark pair or a tau-quark
pair are excluded at 95% confidence level up to leptoquark masses of 712 GeV
and 479 GeV, respectively.
