Police have expanded their search for 65-year-old Ian Collett who left his Canning Vale home on Saturday.
Police are now focusing their search for Mr Collett along Albany Highway heading away from Armadale towards Bedfordale.
The grandfather left his home on Saturday when he went for a walk.
There have been several unconfirmed reports of Mr Collett being sighted at various points along Albany Highway.
The last confirmed sighting on the man was around 3.50pm on Saturday at a convenience store on Abernethy Road in Byford.
Police are currently conducting an aerial search along with ground search by mounted officers, 40 police personnel and 50 SES crew.
Anyone who sees Mr Collett is asked to contact Police on 131 444.
Cooloongup man accused of historical child sex offences dies just weeks before trial
Boat owners urged to make safety a priority this Easter
Mundijong man accused of attempting to procure children overseas for sexual activity
PM Anthony Albanese to address nation
Mandurah teacher who raped student to remain on bail
Man charged after allegedly exposing himself to girl on Transperth bus in Lakelands
Fire rips through Golden Bay home
Firefighters battle bushfire near Nambeelup
Alcoa Children's Festival cancelled due to severe weather