In my contacts, why do I have 2 x "Device" listings for one contact?

[Coro11]

This is on a Samsung Galaxy S4 Mini

When you open a contact for editing, there are various tabs across the top for each type of connection that is saved for that contact (eg. Device, Viber, Whatsapp, Google etc).

For some reason, on one of my contacts I have 2 x "Device" listings. They are both the same except 1 had the country code prefix and one didn't.

I can't seem to find any way to remove one of them. I removed the phone no from one hoping it might disappear automatically but no.

 

[SpookDroid]

Do you have that contact saved to the internal memory and/or SIM card and not to a Google/Samsung account? Device and SIM card might appear as a double tab.

 

[Coro11]

They are not saved to the SIM card. If I save a no to the sim card it then shows up in it's own tab "SIM"