To stop an image appearing on the site you are able to deactivate this in the media centre.
To do this:
Click Media Centre.
Use the search options to find the image, then click the image. It will appear in the box on the right.
On the Settings tab, clear the Active checkbox, then click Save settings.
(Optional) For permanent removal, click the Categories tab.
Assign the Sample Content category, then click Save settings.
Raise a new case via the Digital Assistant to request removal of the image.
Changes made to images in the media centre can take up to 24 hours to populate across the site due to caching on our servers.