A search for a missing man was launched after an abandoned car was discovered.
Sussex Police launched a joint search operation with the coastguard to find a missing man after his car had been found in Marine Parade, Seaford just before midnight.
The man, identified as James Turner, 28, has been missing from his home in Palmers Green, north London, since Tuesday.
The Metropolitan Police were called after concerns were raised about his welfare and they could not find him.
A spokesman for the Metropolitan Police said: "It is believed he may have driven to the Seaford area of Sussex and searches, with the assistance of the Coastguard, have been carried out.
"James's family are growing increasingly concerned for his welfare and are appealing for anyone who has seen him to contact police."
They were searching well into the early hours of the morning before the operation was called off.
Police and coastguard will be resuming their search this morning.
A spokesman for Sussex Police said: "Police and Coastguard searched the shore and sea around Seaford late on Tuesday evening (24 June) and into the early hours of Wednesday, after a car belonging to man reported missing from North London had been found abandoned in Marine Parade, Seaford, shortly before midnight.
"The searches are resuming this morning, Wednesday (25 June)."
A spokesman for the Met said: "Anyone with information is asked to contact Enfield Missing Persons Unit on 0208 345 3332. Alternatively, contact the charity Missing People on 116000."