DARWIN, Australia -- An Australian Navy patrol boat sank an Indonesian fishing vessel in a collision in waters off north Australian early Saturday, a defense spokesman said.

Hmas Geraldton was patrolling within the Australian fisheries zone when it collided with the wooden vessel at Margaret Harries banks, 360km northwest of Darwin, about 0300 A.M.

(1800 GMT), Royal Australian Navy operational controller Captain Bill Overton said.

The five Indonesian crew were rescued without injury and the patrol boat was not damaged, he said.

"Whilst investigating a possible illegal fishing vessel, there was a collision between the Geraldton and the Indonesian fishing vessel," Capt. Overton said. "The Indonesian vessel was abandoned by her crew and the crew were rescued by the Geraldton unharmed."

Naval officers from Sydney and Cairns will begin an inquiry in Darwin on Tuesday into how the collision occurred.

"It appears there was a radar contact, which the ship plotted to be inside the fisheries zone," Overton said. "The ship (Geraldton) had its lights on; There was no moonlight."

Overton said the Geraldton was only 200 meters away when it saw the fishing boat, which had no lights.

Both took evasive action, he said.

"The ship (Geraldton) recognized that there was a possibility of a collision and veered away from it, but there was a collision," he said, AFP reported.

The patrol boat brought the Indonesian crew to Darwin on Saturday afternoon where they were handed over to immigration authorities and met the Indonesian consul.

They will not be charged with fisheries offenses as any evidence was lost with their boat, Capt. Overton said.