A leakage connection for connecting a leakage pipe to a fuel injector which is inexpensive to produce and that can be easily and reliably mounted can be obtained by configuring a security device as a snap ring that can be inserted in a nipple groove configured on the periphery of an insert. A bore groove is configured in the inner peripheral wall of the bore and corresponds to the nipple groove. In the mounted state of the leakage connection, the snap ring, with a part of its wall thickness, lies in the bore groove and with the rest of its wall thickness in the nipple groove, thereby preventing the leakage connection from being unintentionally withdrawn.