Malcolm is a white male, of a heavy build, with light brown balding hair, he wears glasses and has blue eyes.
He was last seen in Chippenham, Wiltshire on 29 September and has links to Worthing and West Sussex.
He may be using the rail network to travel.
Police are concerned for his welfare and ask members of the public not to approach Malcolm if he is seen but to call 999 immediately quoting 47200169926.