We empirically analyze the illicit trade in cultural property and antiques, taking advantage of different reporting incentives between source and destination countries. We thus generate a measure of illicit trafficking in these goods based on the difference between imports recorded in United States' customs data and the (purportedly identical) trade as recorded by customs authorities in exporting countries. We find that this reporting gap is highly correlated with the corruption level of the exporting country as measured by commonly used survey-based indicies, and that this correlation is stronger for artifact-rich countries. As a placebo test, we do not observe any such pattern for U.S. imports of toys from these same exporters. We report similar results for four other Western country markets. Our analysis provides a useful framework for studying trade in illicit goods. Further, our results provide empirical confirmation that survey-based corruption indicies are informative, as they are correlated with an objective measure of illicit activity.