An Indonesian fishing vessel has been destroyed at sea after Australian authorities allegedly discovered illegal activity in a marine park near Darwin.

Three vessels were allegedly found to be illegally fishing in the Ashmore Reef Marine Park, about 840km west of Darwin, during a weekend in May.

About 179kg of trepang, also known as sea cucumber, and 5kg of fresh fish were seized as well as fishing equipment.

One of the vessels was also seized and “disposed of at sea”, Australian Border Force said in a statement on Tuesday.

The crew from that boat were transferred to the two other vessels and they were escorted outside of the Australian exclusive economic zone.

Maritime Border Command Rear Admiral Mark Hill said illegal foreign fishing attempts had decreased in recent years but the threat remained.

“Across the region, foreign fishing fleets are moving from their usual fishing grounds to explore and exploit new ones,” he said.

“Our message to unauthorised foreign fishers is simple – we will intercept you, you will lose your catch, your equipment and possibly even your vessel.”

Nationwide News Pty Ltd.