"There must be no residual data from the former object". IMHO, the only place a residue can be found, is on the harddrive. This means that 'a copy of a mdf' file is not the place to search for residue's. You need a stolen hard drive, sectorscanning and some deeplevel i/o knowledge on MSS. Not an obvious scenario. If someone has OS access , then sectorscanning is not the softspot to aim for. 😉

But there must be people around here much more into this than this little DBA 😉