A dual fuel fuel-injector including a first nozzle body having a plurality of respective receptacles, a plurality of nozzle needles, each having a stroke that is controllable by a control fluid and at least one associated control chamber. The plurality of nozzle needles include a plurality of first nozzle needles, each being axially displaceable in the first nozzle body of the dual fuel fuel-injector for selective discharge of a first fuel, whereby the plurality of first nozzle needles are arranged in the first nozzle body in the plurality of respective receptacles. The dual fuel fuel-injector also includes a mixed leakage collecting channel communicatively connected to the plurality of respective receptacles, and a mixed leakage discharge channel on the dual fuel fuel-injector and in communication with the mixed leakage collecting channel.