The Australian Border Force (ABF) is responding to reports of an illegal foreign fishing vessel in waters off Western Australia's remove northern coast.

A local tour operator told the ABC he saw the boat this morning in mangroves, about 370 kilometres north-west of Broome.

It comes just one day after 20 Indonesian fishermen were fined for illegally fishing sea cucumber, shark fin and sea urchin in the same area, earlier this month.

Thirteen others were taken out of Australia's fishing zone, with authorities destroying three foreign fishing boats.

Peter Tucker, who operates Kuri Bay Sport Fishing Tours, alerted the ABF after his colleague spotted what appeared to be another foreign boat during this morning's excursion.

"The tides at the moment are very big up here and so they were deep in the mangroves," he told the ABC.

"Two gentlemen were seen talking and laughing on the deck of the vessel."

Mr Tucker said authorities needed to work more closely with locals and Indigenous rangers to deter further illegal finishing by foreign vessels.

"It looks like it's an ongoing situation — they've been here for last three or four months on mass," he said.

"The Australian authorities need to be much more proactive."

Illegal fishing damaging unique Australian environments

In a statement, the ABF said it was working closely with the Australian Fisheries Management Authority (AFMA) to detect, intercept and apprehend those conducting illegal fishing in Australia's Exclusive Economic Zone.

"Persistent illegal foreign fishing activity continues to threaten fish stocks and damage some of Australia's most unique and valuable environments, including marine parks such as the Kimberley Marine Park," the statement read.

"We are committed to protecting our vulnerable marine resources and delicate ecosystems through the targeting of irregular foreign fishing in Australian waters."

Mr Tucker led the ABF officials to four foreign fishing vessels in the mangroves of Kuri Bay, about 220km north of Derby earlier this month.

Authorities later confirmed three of the four boats had been destroyed at sea, with 20 of the 33 fishermen taken to the Australian mainland for prosecution.

A haul of 700kg of sea cucumber, 4kg of shark fin, 4kg of sea urchin and 2,450kg of salt was found on the boats.

Punishments described as 'pretty pathetic'

Eleven Indonesian men faced Darwin Local Court on Thursday, with all pleading guilty to using a foreign boat to fish in territorial sea.

One fisher, believed to be a captain, was sentenced to one-month jail, which was suspended for two years.

Mr Tucker described those punishments as "pretty pathetic".

"They're coming onto our sovereign land, and doing what they like, and they're very brazen so it is a concern," he said.

Previous incidents had prompted a national debate over the country's maritime policies, with farmers flagging concerns over the biosecurity threat .

Border protection has become a pressing issue in the Kimberley, with a surge of boat arrivals in recent years.

According to the AFMA, 216 foreign fishing boats had been intercepted between July 1, 2023, and April this year, compared to 125 boats in the 2022-23 financial year.

Meanwhile asylum seeker vessels have arrived at Truscott and Beagle Bay in recent months.