An image of the last known sighting of missing firefighter Anthony Knott has been released by police.
The 33-year-old was last seen at a pub in Lewes, East Sussex, during a work night out on Friday 20 December.
He had been with a group of friends at The Lamb pub in Fisher Street, but for unknown reasons he left the premises alone at about 19:16 GMT.
The image shows him walking up Market Street - towards the pub - at 19:41, 20 minutes after his phone was turned off.
Specialist teams have carried out extensive searches of the area surrounding the pub and the open-air Pells Pool area, which has been severely affected by flood water over the past few days.
Ch Insp Sarah Godley said: "We have reviewed CCTV footage from a number of premises such as homes and businesses, and we are continuing to retrieve and review further footage as we attempt to find out what happened to Anthony.
"Our searches have included local officers, drones and the dog unit, and we have also been assisted by London Fire Brigade, East Sussex Fire and Rescue Service, the National Police Air Service helicopter, Sussex Search and Rescue and the Coastguard agency in our quest to locate Anthony."
She said: "The area we have searched includes Pells Pool and Pellbrook Cut, as well as bins, street furniture, alleyways and dark areas.
"In addition to the local area, we have also extended our search of the River Ouse north towards Hamsey."
Ch Insp Godley added that a further search of the Pells Pool area and the river would be carried out over the weekend as the natural water level falls.
"We will continue to search for Anthony until we get the answers his family are so desperately seeking. Seven days on, our priority remains to find him," she said.
Police have said they are "growing increasingly concerned" for Mr Knott's welfare.
There have been no signs that the 33-year-old, who had been due to return home to Orpington in the early hours of Saturday, had left the town.
Mr Knott, who is 5ft 8ins (1.73m) tall, was wearing a black long-sleeved top, dark denim coat, dark jeans and black shoes.