There is a way to. It has something to do with changing the name of the file(s), creating new blank files with the same name, and then setting permissions and deleting the originals, then deleting the blank new files. I have had this happen to me twice, and in both cases the files that cannot be deleted had permissions of 000. Changing these permissions to 444 or higher (probably to anything other than 000) will allow them to be deleted. Though not an answer, I hope this information at least points you in the right direction.