SYDNEY (AP) — The family of an Australian woman who was fatally shot by a police officer in Minnesota in July has demanded a more rigorous probe into the incident after a prosecutor cast doubts on the investigation.

Hennepin County Attorney Mike Freeman last week said investigators "haven't done their job" in relation to the shooting of Justine Ruszczyk Damond by Officer Mohamed Noor in Minneapolis.

Reading a statement to media in Sydney, Damond's father John Ruszczyk said Thursday that his family is deeply concerned about the possibility that "the initial investigation was not done properly and with the greatest integrity or sense of completeness."

He says they "implore Mr Freeman and the prosecutor's office to continue to pursue a rigorous investigation and examination of evidence of the events leading to Justine's death."