article_snippet.sent: Scroll down for video .
article_snippet.sent: Filmmaker Leon Lee, who is based in Canada, is the man behind the documentary.
article_snippet.sent: told Daily Mail Australia.
article_snippet.sent: As it would have been impossible and very dangerous to shoot in China, Mr Lee filmed in several other countries and obtained footage from Mr Lee sources in China.
highlights_snippet.sent: Documentary will air on SBS One’s Dateline program on Tuesday night .