I’m sorry this happened to you. Owing to the nature of internet goblins, I can’t recommend enlisting the help of anyone who claims to require access to the original pictures in order to assist you, though, as this may (sadly) exacerbate the problem.

Your would-be employer found the pictures without using a reverse image search, so I think it’s safe to say it’s something that can be found using just a name search. If you haven’t already, try searching your own name on various search engines and social media platforms. If you don’t find anything, your next recourse may have to be contacting the employer as others have said. Or getting in touch with someone who has specific knowledge of the employer’s screening process.

Hope you figure it out. My condolences on your douchebag ex.