The family of a 26-year-old Bunbury man missing in a remote area of the South West since June 2021 is launching its own search party as WA Police continue to investigate his disappearance.

Corey O’Connell's sister Haylee told Liam Bartlett on 6PR Mornings the disappearance of her brother, who was last seen on Brockman Highway near Jalbaragup at 7am on the morning of June 24 last year, was out of character, after his vehicle ran out out fuel.

His car and belongings were found months later but Corey hasn’t made contact with family or friends since last being seen walking along Brockman Highway, south of Nannup.

"The narrative for about six months and some rumours that had come through to us was that he had been living off the grid with someone in Manjimup," Haylee told Bartlett.