There are growing concerns for 65 year old Ian Collett, a Perth grandfather who hasn't been seen since Saturday.
Mr Collett suffers dementia, and may have become disorientated on a walk from his Canning Vale home.
He had been spotted by members of the public in Byford on Saturday afternoon carrying a drink from McDonalds, and was later seen on dashcam footage on the corner of Albany Highway and South West Highway in Armadale.
Police have confirmed another sighting of Mr Collett at midnight on Saturday, on Albany Highway between Coglan Road and Jarrahdale Road in Mount Cooke.
Forty police officers including the mounted squad and air-wing officers have resumed the search for Mr Collett today.
They're being supported by 50 SES personnel.
Crews are focusing at the 10 km area from Armadale on Albany Highway in a southerly direction towards Albany.
Police are asking anyone who lives along Albany Highway between Armadale and Albany, who has CCTV cameras to check if they show Mr Collett walking past their homes.
Anyone who was travelling along Albany Highway between Armadale and Albany from 5:35pm on Saturday until now, who has a dashboard camera is asked to check the vision to see if it recorded Mr Collett.
Anyone with information regarding his whereabouts is asked to call police on 131 444.