Can't remove old SSH key from user

My user account appears to still have an old SSH key associated with it that allows access access to the repo but is not listed in the SSH key section.

The SSH key allows commits under my name but assuming that the public key is assigned to another account.

We have the username and pass for the other account but not the email address. We have no way to login as the user to remove the key or to identify the email address (login with username is no longer supported)

Through trial and error we managed to identify the email address used to create the account and now have access. However removing the user from the team and all permission groups does not revoke access to the repos. The associated key is still valid and the user can login and view all repos. This account was an old 2014 account with an old RSA Key (<2048 ).