Olive oil has played a prominent part in Mediterranean culture for over 2,000 years and is beloved by foodies the world over.

However, the industry has a dirty little secret.

A lot of the "Italian extra virgin olive oil" isn't what it says on the tin. Sometimes it's not extra virgin, sometimes it's not Italian — and sometimes it's not even made from olives.

Here's what you need to know about one of the world's most lucrative criminal endeavors.

*An earlier version of this article included a photo where the Olive oil label iO was visible. The inclusion of this brand was not intentional and not meant to imply the group was guilty of the crimes described in the article. We have changed the photo at the request of iO.