The nine young North Korean defectors at the centre of a diplomatic storm.
A war of words has broken out over the children - all thought to be orphans - who the UN believes were sent back to their authoritarian homeland by China last week.
The organization said it was concerned about the return of the children to North Korea, where they could face severe punishment for having fled.
Meanwhile, Beijing warned the UN against making "irresponsible remarks" about the children.
A foreign ministry spokesman said the nine had returned to North Korea on May 28 holding valid documents and denied that Pyongyang had sought to have them returned.
The footage was released by a South Korean lawmaker to bring media attention to the issue.
Professor of law, Park Sun-Yung, a vocal supporter of North Korea defectors, said she hoped the video - and resulting publicity - would prevent Pyongyang from executing the children.
Hundreds of North Koreans attempt to defec
