How do we get the property we purchased when a contravention / fraud occurs?

We (the Buyer) entered into a vessel purchase contract and paid a large deposit and one of the two sellers (the vessel broker) stopped interacting with us after we got the deposit. To assist us in keeping our deposit safe, he gave us a Certificate of Origin of the ship on our behalf and transferred the title to us. Since then, he has missed the contract deadline for repairs / upgrades. Since he “disappeared,” we called the other seller who was shocked to know that we had paid the deposit as the broker told him the payment had been held up by the bank because of a foreign account (which wasn’t — it was from Chase Bank USA). Stupidly, we haven’t done our due consideration. A background check indicates that he has some great views against him/her, so we do not have the power to pay him/her. In addition, the contract specifies that the funds should be payable to the broker and distributed between the two sellers. The vessel’s owner (not the broker) owns the vessel. Our position is that we want the ship as it is a rare and valuable thing for our business.