Police are continuing to search for missing Oundle man Lyndsay Prior.
Mr Prior (45), who is also known as Bert, has not been seen since he left his home in South Road at 2pm on Thursday, January 21.
Specialist search teams have spent the last week looking for Bert, who left home without his mobile phone, wallet and glasses.
Bert is white, about 5ft 11in tall and of medium build. He has very short grey hair with a grey thin goatee beard. When last seen he was wearing blue jeans, a black anorak style jacket and brown ankle boots.
A Northamptonshire Police spokesman said: “It is believed Mr Prior had some sort of fit the day before he went missing which rendered him unconscious. He was having lunch at home with his landlord on Thursday, January 21 when for reasons unknown he got up and walked out of the house without saying a word. He has not been seen since.
“Bert has many friends that he could seek shelter or help from and they might not know he has been reported missing, Bert himself may not know he has been reported missing either.
“Bert, or anyone who thinks they may have seen him in the last week and hasn’t yet spoken to the police, is asked to call 101 immediately.”