Studios have found out that props are valuable items for use in theme park attractions, etc. So they don't want every Tom, Dick and Mary walking around with one. The fact that, historically, crew members and actors have taken home costumes and props and sold them later, is well known. It is difficult with the level of quality in most desirable fakes, for the studios to prove a prop or costume piece is from their actual film. I think most studios rely on the scare tactics of their lawyers to get collectors to just relinquish their items they did not knowingly purchase illegally. My advice: if someone saying they represent such-and-such studio, and say they are investigating stolen props from (film name here), tell them the prop you have is suspicious as a fake, and that you are instituting legal action against the person who sold it to you! Tell the person (or respond to a letter) saying you will require proof in the form of provenance like pictures and property/wardrobe inventory to help you in your investigation. NEVER turn the prop/costume over to anyone without written proof from the proper authorities that it is a stolen item. You are within your legal rights to do this. You are not responsible for the original "theft", even if "obtaining/keeping stolen property" is against the law. You paid good money and paid that money "in good faith" so you are not the criminal. If the Studio or original owner of the prop/costume wants to pursue the issue; let them. If they prevail in proving the goods are stolen, then surrender the items to the proper authorities and lawyer-up and go after the person/company who sold the item to you to get reimbursed for the item.