I was searching my suppliers' website in google and I noticed a "proxy" website that seems to have gotten indexed.

This proxy website has the same EXACT content of their website, only the URL is something like:
theproxywebsiteinquestion.bla/index.php?q=aHR0cDovL3d3dy5tZXJhbA%3D%3D

The internal links are exactly the same as above!

This is an extremely frightening aspect for me, as I fear my website may have also been indexed by this shoddy website. A link to my website is contained on one of the websites I located in google.

What can I do to get rid of this website? So far, I placed a rewrite in my htaccess to deny any referrers from this website, but google doesn't use referrers...