Coroner Rusty Clevenger said the badly decomposed body was "unrecognisable".
"They are understandably upset at the revelation since her final disposition was to be cremated in 2015," he told reporters.
"I will be exploring legal means to have her family's wishes carried out for final rest," Clevenger said. "I have been contacted by officials and the State Attorney-General about this case and I will be providing any info my office may have."
Mortuary malpractice is surprisingly common. In 2016, a jury awarded a Massachusetts family $150,000 after a botched burial.
Lincoln White Sr, a Korean War veteran, was cremated in 2014 but the funeral home lost his ashes. In a tragic twist, the funeral home also lost a portion of the cremated remains of Lincoln's late wife, Lucille, whose ashes were being preserved so they could be buried alongside his.
Closer to home, NSW Health Minister Jillian Skinner was forced to admit a devastating error that saw a baby's body cremated against its family's wishes.
Two babies had been switched accidentally at Royal North Shore Hospital. The baby's family had requested a buries but the mistake wasn't recognised until after cremation