How are some items in sitecore web database disappearing automatically

We have a strange scenario in our production. Every day we see one of our multisite parent item is deleted from the web database.

Each multisite is region specific and has region language version and default English as fallback version.

1. we reviewed our items publishable check box, it is set to publishable
2. our lower environments cannot access the prod master/web databases to overwrite
3. Reviewed our publish logs on any delete activity- nothing was found there
4. Delete empty versions setting is true in Sitecore settings
5. we have set up publish server following the scalability guide

We see sometimes our language definition items are also getting deleted. Need help as we are not able to think of what is going wrong.

We engaged Sitecore team for support. The issue is with Unicorn Dataprovider that we are using. The Dataprovider is not supposed to make it's way into higher environments as per Unicorn documentation. We removed the provider in Production boxes and everything looks fine now.