A corpse was found in the sea, some 18 miles off Tigné Point, according to the police.
The body, which has not yet been identified, was found in a badly decomposed state. The alarm was raised by a fisherman around 2.40pm. The victim was brought ashore at Haywharf later.
It is not known whether the body belongs to a migrant who might have attempted the crossing from Africa to Europe.
Police are investigating. A magisterial inquiry has been ordered.