[CentOS] Zombie users in Centos6

Geetings,


I have a machine with PAM using LDAP.
Some old users do not disappear from:

  * getent passwd

But, they are not in:

  * /etc/passwd or
  * LDAP

Where are they?
Any idea?

Please, I am affraid of ghost. :-(


TIA


-- 
Cosme Faria Corrêa