Police are concerned for the safety of a man believed to be known as ‘Hungarian George’, who was last seen near the sea on Mablethorpe beach on Thursday afternoon.
The man was last seen close to the sea level with the Dunes Bar at 4.10pm on July 23.
He is described as white, five foot, nine inches tall, of muscular build, and with short dark hair.
The Mablethorpe, Skegness and Donna Nook coastguards have searched for him on the main promenade both north and south.
A police drone was also used to search the immediate area.
The RNLI Mablethorpe also searched the water and a coastguard helicopter was called in when light started to fade.
After an intensive search of the water both lifeboats were stood down for some rest at 2am with a retasking planned at first light.
Anyone with information or who has seen a man matching this description should contact Lincolnshire Police on 101 quoting incident 420 of July 23.