NSW detectives hope a $1 million reward will help catch those responsible for the murder of Penny Hill 28 years ago.
The family of a young NSW nanny who was murdered nearly 30 years ago are hoping a $1 million reward will help solve the cold case and bring them peace.
Twenty-year-old Penny Hill was found unconscious with severe head and facial injuries near Coolah, in the state's central west, on July 8, 1991. She died in hospital nearly two weeks later.
Ms Hill had just moved to the area and started her first job as a nanny at the Black Stump Motel only three days before her body was found.
Two coronial inquests - in 1992 and 2012 - have both delivered open findings into Ms Hill's death and no-one has ever been charged.
The NSW government on Monday announced a $1 million reward for information leading to the arrest and conviction of those responsible for her murder.
Detective Acting Superintendent Mark Henney appealed for anyone with information about the "horrific murder" to come forward.
"We are committed to getting justice for Penny and providing answers for her family," he said in a statement.
Penny's mother Jeanette Hill said she and her family had endured "immense agony" and was reminded every day of the life she never got to live.
"It has been almost three decades that we have been searching for answers and once again we ask that anyone in the community who might know what happened to our daughter, please come forward and help police," Ms Hill said.
"Our family, and our Penny need peace."