@Matthew – are you really sure about the location?
Did you check the links and their paths in the Links Panel?
Maybe, it's good showing an example here posting a screenshot* with showing the link information.
Otherwise: maybe a script can help. A panel that is going through all paths of all linked images hunting for double entries and showing them.
To make it automatically update every time a link is added or removed seems doable. However, such a listening mechanism could degrade overall performance a bit (or even more depending on the amount of linked images).
Uwe
*using the camera icon in the forum software