Find out image origin

Hi

I am getting following in PHP error logs:

PHP Warning: getimagesize(http://avada.theme-fusion.com/classic-shop/wp-content/uploads/sites/48/2015/12/promotion_accessories_img.jpg): Failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found^M
in /home/fasonline/public_html/wp-content/plugins/litespeed-cache/src/media.cls.php on line 1038

I know this is not LS problem. The problem I have is that image file/URL should not be part of any page and I am unable to see it in page code.

The question is — is it possible to find out which page LS finds this image on? Perhaps with some hook/filter?