User with both LDAP and standard passwords

My Gitlab server is primarily using LDAP to authenticate users. However, occasionally there is a need to give access to users who don’t have an LDAP account, so there are a very small number of local users who can login via the “Standard” tab on the login screen.

One of my users now has a problem as he seems to have both an LDAP password and a “Standard” password. He claims that the standard password is insecure and wants it removed. However, I can find no way to access this password via the admin area of Gitlab. All the information there only pertains to his LDAP credentials.

Is there any way I can deleted (or at least change) his local “Standard” password whilst leaving the rest of the account untouched?