Extracting a tar file containing files with Chinese names will make the filenames illegible

Question

On my Mac OS 10.6.8 I had a directory full of files that had Chinese filenames. I proceeded to run tar czf mydir.tar.gz mydir

Now when I untar it with tar xzf mydir.tar.gz, the extracted filenames are all jumbled and no longer the original format or encoding. How do I restore it? I've already lost the original directory so the compressed file is the only thing I can work with.