How do i nuke a security encrypted hard drive?

[thedaddyy]

How do i nuke a security encrypted hard drive?
What procedure do i take? "could it be the procedure i am using?"
If not what can?
There seems to be some kind of security encryption on the hard drives everything i have tried does'nt do anything to it.
I have tried the following with absolutely no joy what so ever

Darik's Boot and Nuke
Eraser
Clear HDD
HDD Low Level Format
KillDisk
Maxtor Power Max

2 drives sitting in front of me they are getting to look like BRICKS MORE EACH DAY........................
I am not interested in whats on them i just wanna use them for backing up.
HELP!!!!!!