A 4.3 metre long rare oarfish washes up in Oceanside, California

FOR the second time in less than a week, a "sea serpent'' - this time a rare snakelike oarfish - has attracted gawkers on a beach.

FOR the second time in less than a week, a "sea serpent'' has attracted gawkers on a southern California beach.

This time the rare, snakelike oarfish washed up on Friday afternoon in Oceanside.

The newspaper U-T San Diego reported that it measured nearly 4.3 metres long and attracted a crowd of up to 75 people.

FIVE-METRE LONG SEA SERPENT FOUND ON BEACH

Oceanside police contacted SeaWorld San Diego, The Scripps Research Institute and the National Oceanic and Atmospheric Administration.

Someone from NOAA retrieved the carcass, which was cut into sections for later study.

While it's unusual to find the deepwater fish near shore, on Sunday last week a snorkeller off Catalina Island found a 5.5-metre-long oarfish and dragged it onto the beach with the help of a dozen other people.

This 5.5 metre-long oarfish was found in the waters of Toyon Bay on Santa Catalina Island, California. (AP Photo/Catalina Island Marine Institute )

According to the Catalina Island Marine Institute, oarfish can grow to more than 15 metres, making them the longest bony fish in the world.

They are likely responsible for sea serpent legends throughout history.