The Uttar Pradesh police on Sunday said that the post-mortem report of Yunus, the key witness to the death of Unnao rape case victim's father, could not determine the cause of his death.

Speaking to ANI, Additional Director General (ADG), Law and Order, Anand Kumar said, 'The post-mortem report clearly says that the cause of death could not be ascertained. Viscera (the internal organs) needs to be preserved for histopathological and chemical examinations. In addition, the post-mortem report also mentions the lack of any anti-mortem injuries on the body.'