Months after she was spotted taking money out of an ATM, the partially buried remains of a Queensland grandmother turned up hundreds of kilometres away near a NSW beach.

The “highly unusual” disappearance and death of Wendy Hansen have triggered a major homicide investigation after she was identified as the body discovered in the popular NSW holiday destination of Coffs Harbour.

Six months after the 63-year-old was last seen alive, NSW Homicide Squad commander Danny Doherty said on Thursday the death was being treated as suspicious.

“The highly unusual disappearance of a loving grandmother, who has been found 800 kilometres from home and no one knows why,” Doherty said.

“We’d like to solve that mystery and provide the answers to the family.”

Hansen’s family, who were not suspected of any role in her disappearance, had held out hope she might be alive after she vanished on February 29, Doherty said.

That hope evaporated when a missing-person search linked her to remains found by volunteers clearing vegetation in dunes at Jetty Beach in Coffs Harbour in June.

“[Her family] reported her as a missing person and were hoping that she’d come back,” Doherty said.

Police issued an appeal for information after the grisly beach find, while a number of items including clothing, jewellery, reading glasses, a book, a backpack and a wallet were also recovered.

But perhaps more important were the things police did not find, such as the grandmother’s phone.

“Obviously that heightens the suspicion,” Doherty said.

Also missing is the 2007 short-wheelbase silver Mitsubishi Pajero Hansen was driving, last seen heading south on Queensland’s Bruce Highway north of Brisbane on the day she disappeared.

Hansen was seen withdrawing cash from an ATM in her home town of Monto, west of Bundaberg and about 400 kilometres away from where her four-wheel drive was captured on CCTV, earlier that same day.

“The trail goes cold from the Sunshine Coast,” Doherty said on Thursday.

Why Hansen was in Coffs Harbour and how she got there would form part of the investigation because she had no known links to the area.

The area where her remains were discovered by volunteers is near a regional train station. Police are investigating whether she used other modes of transport.

It is hoped CCTV footage of Hansen and images of the “unusual-looking vehicle” she was driving might jog someone’s memory as investigators try to piece together her movements and a timeline for her disappearance, Doherty said.

-AAP