Germanic *fánhan

To the germanic infinitive *fánhan my etymological dictionary gives a
reduplicated imperf. sg. *fe-gánh-. It makes use of Verner's law to
explain the past participle *fanganá/*fanginá (*[h]>*[h]). But it
gives no explanation as to *[g] in the *-gánh- stem with which the
reduplicated imperfect form was made. It says however that gothic
imperf. sg. faifâh reflects a younger *fe-fanh- form. In other
germanic languages the *[g] has spread to other forms by analogy
(Ex.: 19. century german inf. fahen, later fangen).

The dictionary traces the proto-germanic form back to IE *pank´ (with
nasalized present stem). Where did the *[g] come from in the first
place?


Håvard


PS. Happy Easter!