The body of a missing Northern Territory gyrocopter pilot has been found by police divers who searched a crocodile-infested river from an underwater cage.

Key points: The body of James Russell and a crashed gyrocopter were found by police on Monday

The body of James Russell and a crashed gyrocopter were found by police on Monday He had been missing since Thursday

He had been missing since Thursday Police believe he hit power poles shortly after take off from Timber Creek airstrip

James Russell, 48, was reported missing on Thursday after flying his gyrocopter from Timber Creek airstrip, 600 kilometres south of Darwin.

It is believed he collided with power lines and lost power shortly after take-off.

After five days of searching, the crashed gyrocopter was found in the Victoria River, not far from the Timber Creek airstrip, at 3:15pm on Monday.

During the "long and challenging" search, Senior Constable Stuart Winter said police divers scoured the murky river using grapple hooks from inside a cage, to protect them from the vast numbers of crocodiles in the area.

He said they used sonar equipment to identify areas of interest before sending down divers.

"We've utilised a cage to put people in the water and then [we] move that cage around," he said.

Police divers found the missing pilot. ( Supplied: NT Police )

"They can reach through the cage and open the door to go a short distance to inspect objects.

"But yeah it's been almost black water, it's mostly touch and feel sort of searching so it's been quite testing, with calculated risks."

While Mr Russell's body has now been recovered, police are still working to raise the crashed aircraft from the water.

"The tides here are fairly hard to predict, we expected to put more lift bags on the wreckage last night but the tide didn't recede for us," Senior Constable Winter said.

"We're going to go back in a couple of hours time, on the low tide and attach more lift bags and hopefully float the aircraft to a position where we can recover it from the water."

A report will be prepared for the coroner.

The crash came just 10 days after a helicopter crashed in Kakadu, seriously injuring its three occupants.