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/82690/wtmpclean-0.6.7.tar.bz2
Source: https://packetstormsecurity.com/files/82690/wtmpclean-Record-Wiper-0.6.7.html