This paper examines the identity of null objects in Korean. For the last two decades, null objects in this language have been argued to derive from either base-generation as an empty pronoun or ellipsis/deletion. To resolve this controversial issue, we scrutinize some previous arguments supporting one analysis or the other for null objects. We set forth a background for the discussion of them, starting with the diagnostic that Chung et al. (2011) uses to distinguish VP and TP ellipsis in English. We then turn to Hoji's (1998) and Ahn and Cho's (2011) test utilizing the availability of a sloppy-like reading, and then to Hoji's (2003) and Bae and Kim's (2012) probe employing R-expressions. Showing that all these diagnostics are not effective as much as they have been claimed to be, we use the new test capitalizing on the extraction out of an ellipsis site, arguing that null objects in Korean derive from deletion/ellipsis rather than base-generation as pro.