Need to delete fingerprint and password Samsung S6 from open phone

[AC Question]

I have a Samsung Galaxy S6 (Telstra plan) 32GB 3 months old. Running Android Version 5.1.1 Kernel Version 3.10.61-5999799. I have owned phone since new but think someone else may have played around with fingerprint function. I am not locked out of the phone and use a 4 digit pin for access. All other features on phone work fine. When I try to access the fingerprint manager, it asks for and wont accept my fingerprint or any of my usual passwords. As a result, I can't access the manager to delete the info. How can I remove the fingerprint/backup password settings from my non locked out phone without a complete reset?