compensation of royalties

During my travels in australia, my friend and i befriended an owner of a small tshirt business. We gave him an idea, and used a photo of myself for the tshirt design. He as always maintained that he will have opporunities for us and that he would not leave us in the dark if he started to make money. He has now sold thousand of these tshirts with my face on them, and we have yet to see any type of compensation. We never had any written contract, only good faith and verbal agreements. We are now back in the U.S. so contact with him has been difficult. Is there any possible legal proceedings?