  A search for events containing two or more high-transverse-momentum isolated
leptons has been performed in ep collisions with the ZEUS detector at HERA
using the full collected data sample, corresponding to an integrated luminosity
of 480 pb^{-1}. The number of observed events has been compared with the
prediction from the Standard Model, searching for possible deviations,
especially for multi-lepton events with invariant mass larger than 100 GeV.
Good agreement with the Standard Model has been observed. Total and
differential cross sections for di-lepton production have been measured in a
restricted phase space dominated by photon-photon collisions.
