images listed in taglist do not exist in database?

i have just noticed that some tags are present in my site's database that relate to images that were once on the site and now are not.. so i can search for the keyword and the photos appear (with url for the image) in the search results page..  yet the image is not on the server.. so i see a mostly white page with some text; e.g.:

does anyone know how to resolve this?