How do I remove duplicate contacts from Google+? I have a problem with my contacts in conjunction with google+.
Like most, I had already a lot of people in my contactlist, which is synced with the contacts in google mail. With google-plus, I have added a lot of people to circles. Those people from Google+ are now all individual entries in my contacts, but only on the phone.

After deletion I recognized, that all people are also removed from my circles.

So how to add people to circles, without having them appear as duplicate contacts?

EDIT:
Thanks anyone, yes, some of you are right - it seems that those people are put in an extra list "Other contacts" (also visible in the web interface). You have to uncheck this group in the settings > displaysettings. Can someone of those people put this in an answer, so I can accept it, thanks :)
When you Circle someone in Google+, it also adds them in the "Other Contacts" in Google Contacts.

Simply de-select "Other Contacts" in the Contacts app to remove these contacts from your view.

When multiple show up (in Google's New Contact vies), deselect the person's old contact info from ANY circle. That way Google doesn't "hang on" to them, they get integrated into your existing contact for that person.