Western Australian police are investigating after a bizarre discovery on a remote island 300 kilometres west of Broome.

An ornate arrangements of sticks, stones, and a makeshift cross thought to be recently created graves were discovered in October at Imperieuse Reef in the Rowley Shoals Marine Park,

Skipper Harley Cuzens said it was a shocking sight.

“I spotted the sticks poking up from a distance, so headed over for a look and thought, ‘Bloody hell, these are graves’,” he told the ABC.

“It was very eerie and actually quite upsetting.

“There was one with a big cross and others with a lot of stones and sticks, and a few other mounds which I suspect are also burials.”

The remote Rowley Shoals Marine Park is a 20-hour boat trip from the WA mainland. Image: Google Maps

WA Police said officers would travel from Broome to the islands, which are accessible only by boat, to examine the site.

“Following recent approval from the state coroner, Broome detectives will conduct an examination of the reported site to verify if any human remains are present,” the statement said.

“At this stage, human remains have not been located at the reported site.

“We will deploy local forensic resources initially but it may require further deployment of specialist forensic resources.”

The remote area area is popular for deep-sea fishing and is known to attract illegal foreign fishing crews who harvest fish, shark, and sea cucumber.

It is a 20-hour boat journey from the Australian mainlain.

Earlier this year, 11 Indonesian fishermen shipwrecked by Cyclone Ilsa were rescued from the Rowley Shoals after six days without food and water.

Australian Maritime Safety Authority said at the time they were rescued only after a surveillance flight spotted their makeshift camp and beached boat on a small sandy island.

Nine other fishermen remain missing after the terrifying ocean ordeal in April. They are presumed dead, and it is not yet known if the possible graves are linked to the shipwrecked Indonesian boat.

“The survivors reported that there had been two fishing vessels with 10 crew each, but one vessel had sunk in the extreme conditions of the cyclone, ” Australian Maritime Safety Authority said in April.

“The remaining vessel managed to rescue the only survivor before being washed ashore on Bedwell Island.”

At least 18 fishermen are believed to have died in storms and sinkings in the area in the past two years.