The US should apologise to and compensate the families of victims of Japanese World War II medical atrocities for its role in a subsequent cover-up, a visiting scholar said. Victims of the 'forgotten medical atrocities' were mainly Chinese and included people from Hong Kong, said Dr Nie Jing-bao, a lecturer from the University of Otago's Bioethics Centre in New Zealand. The US had been involved in covering up Japanese human experimentation similar to that of Nazi Germany, said Dr Nie, who is visiting Baptist University. He said none of the Japanese doctors involved had been prosecuted and had instead gone on to take up prominent positions. 'Justice has never been done yet, even after 50 years . . . Thousands of people died,' Dr Nie said. 'When I work on this topic, I often feel the ghosts of the victims are watching me.' The Japanese Imperial Army's infamous Unit 731 is believed to have killed more than 3,000 mainly Chinese and Russian prisoners of war in experiments that involved vivisection and injection with diseases such as typhus. The US freed members of the unit in exchange for the results of their experiments, scholars say. Racism and national interest had combined to prompt the US to cover up the atrocities, Dr Nie said, but the US should now apologise and compensate families of those killed.