You are likely screwed. You two are partners and you both own the content and have equal rights to it unless you have some real proof otherwise. This same problem cost me $187,000 in 1994 (software code, not web site).

Bottom line: $107,000 legal fees, $80,000 settlement. It cost PLENTY when partners don't agree. I suggest you be nice and come to a settlement without involving attorneys.

The one thing you have in your favor . . . you may be able claim 50% of all his revenues (and vice versa). That would be a much easier to make that case fr than to make a case for rerecinding his rights to the content. In my case, the partner quit and then claimed 50% of the revenues earned by my selling the program. He wasn't going to do anything with it, just leach off of me.

The relevant law is copyright law. So if you do get an attorney, you need an intellectual property guy.