Bob, 85, suffers from dementia and was last seen via doorbell footage at around 3.54am on Tuesday.
At the time, he was walking in Galloway Drive towards the direction of Station Road and Dartford Heath. He was wearing a light blue-grey coat and trousers.
Police said he has a distinctive stooped walk and his family are concerned for his safety.
Detective Inspector Kirsten Hadleigh from Met’s South East Public Protection Unit said: “Bob is vulnerable and suffers with dementia which is why it is important we find him fast. My concern that Bob is in danger increases every moment that he remains missing.
“We are now appealing to the public for their assistance, I would like to hear from anyone who may have seen Bob over the past few days.
“I would urge people to check dash cam or other camera footage from the Dartford Heath/ Shepherds Lane areas from 4-5am on Tuesday, 24 October. This footage may have captured Bob and this could prove vital in our efforts to find him.”
The police investigation continues, anyone with information is asked to call 101 or post @MetCC quoting reference 23MIS035913 to provide information.
