file recovery – Can an edited photo on my iPhone be recovered if the original has been deleted?

For personal reasons that will not be detailed here, I have strong reason to believe that an unauthorised person has had access to my iPhone. They have used that access to edit my photos and videos, and also to delete the originals.

Is there any way I can obtain the originals of the photos and videos? This being an iPhone, they have been backed up to iCloud.