[H] zip remains

[Winterlight]

I have a script that uses Winzip to backup certain folders on secure 
encrypted drives.  The folders are backed up into individual zip files. The 
script "updates" the zip file adding or changing only new or changed files.

I am wondering when Winzip does a "Update" does winzip leave traces behind. 
Does it in any way delete the original zip so it ends up in the un-encypted 
swap file?

The temp file Winzip uses I am not worried about, as the machine uses a 
large RAM drive as a temp folder

thanks