Remove user from search list

I want to remove a user from user search list. How can this be done in SharePoint 2007? I have already tried to user below settings, But I could able to add under contributor group afte few days!!1 GO to Central Administratopn >> User Profiles and Properties >> View User Profile Under custom import, added additional user filter contition to block that AD active user.

(&(objectCategory=Person)(objectClass=User)(!(mail=ITTest*)))