Police have confirmed that a body discovered on a rural property in Terragon belongs to Yvonne Whear, the 73-year-old grandmother who vanished almost eight months ago in northern NSW. The announcement was made on Tuesday, after the remains were found last Monday in half a metre of water inside a livestock trough.

The body was discovered by two trail bike riders on the property, about 20 kilometres south of Murwillumbah, where Whear was last seen. It was in a deeply decomposed state. Investigations into her disappearance are continuing, and police have now launched a homicide investigation.

Acting Superintendent Matt Zimmer said police were focused on uncovering what happened and identifying those responsible. “Yvonne was a mother, grandmother, a great-grandmother and a person who was clearly loved by those around her,” he said.

“While we can now provide some answers to her family, there are still significant questions about what happened to her and how she came to be where she was found.

He said that “someone knows what happened to Yvonne” and is urging anyone with information to come forward.

“Even the smallest piece of information could prove crucial as we work to establish the circumstances surrounding her death and hold those responsible to account,” he said.

“Yvonne’s family has endured many months of uncertainty, and they deserve answers. We are committed to pursuing every line of inquiry and urge anyone who can assist to contact police.”

Whear, who lived on a small hobby farm in Dungay, regularly travelled to nearby Murwillumbah, which is less than 10 minutes away. Her family had previously said she attended an art class at TAFE on the day she disappeared.

She was last seen on CCTV at the Shell service station on Tweed Valley Way in Murwillumbah at about 3.15pm on February 19. Her relatives described the disappearance as “out of character”.

Her daughter, Gillian Hallac, became worried when she had not heard from her mother for two days, despite the pair being in frequent contact. In August, Hallac said the drawn-out uncertainty was “overwhelming”.

“I miss her advice, her voice, her presence.

“It’s the everyday moments that hurt the most – the ones we never thought we’d lose,” Hallac said.

In the months after Whear vanished, police mounted a broad search effort using drones, helicopters, police boats fitted with sonar, trail bikes, and officers searching in vehicles and on foot. Detectives initially suspected she may have crashed while driving along the winding roads of the Northern Rivers, but concern deepened as neither Whear nor her vehicle could be located.

On September 12, officers searched the Rous River after receiving information that a vehicle may have been detected on the riverbed. During that operation, Whear’s Ford Escape SUV was pulled from the river, but she was not inside.

Police also found her personal belongings in the vehicle. Mobile phone data showed that on the afternoon she vanished she watched YouTube videos and checked her voicemail shortly before 5pm. Her phone was last picked up by a tower near Dungay the following day and was never seen again.