The coastguard, RNLI and Sussex Police have been involved in a major search and rescue operation in Hove after it was reported clothes were found on the beach.
Shoreham RNLI said it had deployed both its lifeboats, announcing on Facebook that they launched at 9.48pm.
An hour later they announced the coastguard helicopter and Brighton RNLI had joined the search.
The operation began late last night (March 2).
A spokesperson for Sussex Police said:
"Sussex Police assisted the Metropolitan Police with a missing person from London in Basin Road South, Portslade.
"For more details about the person and whether they are still missing, please contact the Met Police Press Bureau on 0207 230 2171, or by emailing press.bureau@met.police.uk"