How do you disable graphic listing of recent files after closing?

After closing a LibreOffice file snapshots (vignettes, large thumbnails) for recent files accessed appear.
(I do not know the technical term for this page but the left hand side lists “Open File”, “Templates”, “Create:” with “Help” and “Extensions” at the bottom).
I find this a potential security risk if any of the files contain sensitive data.
How can one disable this feature or am I just being paranoid?

Version: Build ID: 420m0(Build:2)
Ubuntu 14.04 LTS

Please have a look at:

Can I supress the images on the start screen?

Can the new Start Screen in v4.2 be reverted to that in v4.1?

Hide preview for password protected documents

See also: Tagged start-screen + recent-documents.

Using the password option with “save as” works for me. The content is not visible. Now I just need to figure out why the preview appears at closing only.