The man is described as white, 5ft 9ins tall, with short dark hair, and of muscular build. It is believed he is known as ‘Hungarian George’.
The man was last seen close to the sea, level with the Dunes Complex in Central Promenade, Mablethorpe.
If you have seen this man, call the police on 101 and quote incident number 420 of July 23.
Mablethorpe Coastguard posted about the incident on their social media channels over the weekend - after a late night search failed to locate the man.
A Mablethorpe Coastguard spokesman said: “We were paged by Humber Coastguard to reports of a missing male last seen near the waters edge in Mablethorpe.
“We arrived on scene and were met by Lincolnshire Police, who informed us the male was last seen a little after 4pm.
“We performed an immediate hub search and teams from HM coastguard Skegness and HM Coastguard Donna Nook Rescue Team also assisted, searching both on foot and vehicle searches from our hub on the main prom both North and South. In addition, a police drone was used to search immediate area.
“Also, RNLI Mablethorpe Lifeboat Station launched both their ILB (Inshore Lifeboat) & Atlantic to complete water searches North and South from the lifeboat station.
“Rescue 912 Coastguard Helicopter was called in when light started to fade, but had tech in iCal difficulties and had to return to base.
“After an intensive search of the water, both lifeboats were stood down for some well deserved rest. RNLI Skegness and RNLI - Humber Lifeboat Station were then tasked to support the water search and Rescue 22 was called in to complete a search from the air.
“At 2am, our teams were stood down to get some rest with a re-tasking planned at first light.
“Many thanks to all teams and services that have been involved this evening. Excellent team once again.”
The statement added that seven crew members had been in attendance, in addition to four from Skegness and six from Donna Nook, and three RNLI crews. Alongside them were members from LCAT, Lincolnshire Police, and aerial support from Rescue 22 and Rescue 912.
The search continued the following day, but the man had still not been located at the time of going to press.
On Tuesday (July 28), Lincolnshire Police confirmed: “We are still investigating his disappearance and he is being treated as a missing person.”