Unknown actor playing Helmut Berger's father in Una farfalla con le ali insanguinate

[PointedMonkey]

I'm wondering if someone on the forum may be able to identify the actor playing Helmut Berger's father in the 1971 giallo Una farfalla con le ali insanguinate.

Despite the character being a key supporting role who's given his own on-screen credit at the beginning of the film, the actor doesn't appear to be listed in the credits, which is odd.

Several sources online mistakenly credit Wolfgang Preiss in the role, but Preiss actually plays a different character in the film.

Any lead or suggestions would help immensely, thanks.

[Emiliano]

I also looked for him some time ago but I could not identify him.