Walpole police have serious concerns for a man they believe is missing from a campsite near Walpole.
A police spokesman said three friends arrived at Aldridge Cove, on the Nuyts Wilderness Track about 12km west of Walpole, last Monday and camped there for two nights.
They noticed a tent and personal belongings nearby, but during their stay no-one returned to the tent.
The group hiked out and raised the alarm when they returned to Perth on November 20.
Police unsuccessfully searched the immediate area with the help of marine rescue volunteers and Department of Parks and Wildlife officers.
Personal belongings at the scene were labelled 'Rowan Cook', but police "have not been able to establish the confirmed identity".
Police believe the man is 40-year-old Rowan Wallace Cook and that he may have been in the area some time in the last two months.
Walpole police would like to speak to anyone who has camped at Aldridge Cove recently or hiked nearby and may have spoken to the man.
Someone may also recognise his camping equipment.
Anyone with information is asked call Crime Stoppers on 1800 333 000.