Police have stepped up their search as fears grow for pensioner Norman Galbraith, who has been missing for six weeks.
Search dogs and volunteers from the Community Rescue Services team have joined officers as they scoured the River Bann and inland locations between Coleraine, Ballymoney and Articlave in an attempt to find any trace of the missing man.
The 66-year-old was last seen at his home on Queens Avenue, Ballymoney, on July 31.
Concerns have grown in recent weeks as Mr Galbraith normally takes medication for high blood pressure and he is thought to have injured his head in an incident several days before he went missing.
His wallet was found on the Garryduff Road near Dunloy on August 4 and a number of sightings were reported in the Coleraine area, leading officers to believe that he may have been making a journey to his childhood home in Castlerock.
This is a journey that he has made before.
Ballymoney councillor Darryl Wilson said: "Quite a few people from the town would know Norman to see. You would have seen him about in the local supermarket or down the street but he keeps himself to himself.
"I know he did like to go off by himself and travelled on the bus quite a lot. I was speaking to a local bus driver and he said he would go away for the day shopping or to visit people outside the town. That obviously widens the area of search."
The UUP councillor added: "I'm asking people to remain vigilant and to keep an eye out for him and indeed, in the local area, people should check outhouses, barns or sheds in the hope that Norman does turn up safe and well." John Finlay, a DUP councillor for the area, said: "He's a very nice man. I just don't know what has become of him.
"I'm very sorry for his family. Any time he was in our constituency office, he was always very pleasant and very sociable.
"This is very unlike him. I think this is totally out-of-character. I just hope that they find him safe and well."
Detective Inspector Soren Stewart said: "Specialist police search teams along with officers from the tactical support group spent much of the weekend searching for Mr Galbraith.
"Despite extensive efforts, Mr Galbriath remains a missing person. Our resources were bolstered by the support of volunteers from Community Rescue Services. Specially trained police search dogs were also brought in. We covered areas right across Coleraine, Ballymoney and Articlave. Sections of the River Bann were searched as well as inland locations.
"We appreciate and acknowledge the public support and information received to date. Mr Galbraith has been missing for close to six weeks now, causing great concern for his family and friends.
"The hope for any family in this situation is that the missing person will be found safe and well, but our searches must be thorough."
Mr Galbraith is described as being of a small, thin build with grey hair.
Police released CCTV images of Mr Galbraith which were taken in the afternoon before he went missing.
He was wearing a navy fleece, navy tracksuit bottoms and black shoes and it is believed that he was wearing these clothes later than the evening when he was last seen.
Mr Stewart said: "I would again appeal to anyone with any information on Mr Galbraith's movements since July 31 to contact us on the non-emergency number 101.
"I also ask people in the Ballymoney, Coleraine and Articlave areas to check any outbuildings or sheds in case Mr Galbraith sought shelter in them at any point."