wtmpClean is a tool for Unix which clears a given user from the wtmp database.
You can download it from the following link: https://packetstormsecurity.com/files/download/82379/wtmpclean-0.6.6.tar.bz2
Source: https://packetstormsecurity.com/files/82379/WTMP-Log-Cleaner-0.6.6.html