Northern Territory Police hold concerns for 73-year-old John, also known as Jack, who walked away from his property on Strickland Road, Adelaide River.

He is believed to have left his home between 11pm Sunday night and 8am this morning.

John is described as of Caucasian appearance, slim build, with grey hair and a beard.

He suffers from severe dementia and type 2 diabetes and his family and police hold concerns for his welfare.

Search & Rescue Section are conducting search operations for the missing person.

Anyone with information on John's whereabouts is urged to make contact on 131 444 and quote reference P24283763.