Police are looking for public assistance to find Jason Brinkley, who was last seen in the city centre about 4pm on Sunday.

Mr Brinkley, 48, is described as 190 centimetres tall, of solid build and Caucasian appearance.

He had a shaved head and was wearing navy blue cargo pants, a red long-sleeve T-shirt and a red zip hoodie and joggers, police said.

Mr Brinkley, of Isabella Plains, drives a late model BMW 355i sedan with registration AYAA83Z.

Police and Jason's family have serious concerns for his welfare.

Anyone who has seen Mr Brinkley or has information can contact ACT Policing on 131 444.