Within half an hour of launching his boat at Bridge Lagoon, the Humpty Doo local was reeling in a 68cm barra with a two metre saltie in pursuit.

With no one else to help him net the prized catch or distract the croc, Mr Ahrens said he was lucky to get the barra in the boat in one piece.

The long-time Territorian said the $10,000 would be useful to help pay off his mortgage.

Million Dollar Fish Season 6 only launched a month ago, and already seven tagged fish have been caught.

A total of $75,000 in prize money has been won by registered participants across the Territory and Australia.

There are still five months to go as part of Million Dollar Fish Season 6, with 94 $10,000 barra remaining in the competition.

In addition, there are seven $1 million barra (if the $1 million fish is caught, the remaining six turn into $10,000 fish) and four Double-Tagged Barra worth $10,000 to the lucky fisho and $5,000 to their mate.

There are also 20 $5000 charity fish yet to be caught, which will see $2500 awarded to the angler and $2500 to the winner's Million Dollar Fish affiliated charity of choice.

Registered participants of Million Dollar Fish also go in the Lucky Prize Pool, with thousands of dollars' worth of prizes to be won each month.

To register for the chance to become a millionaire, go to www.milliondollarfish.com.au.

Brian Ahrens said: "I've been living in the Territory for 13 years and almost always go fishing at Bridge Lagoon. I decided to take the boat out on Friday morning and, within half an hour of launching, I was onto a red tag.

"A croc seemed very interested in him and had a bit of a go at the fish. As I wound him in I saw the croc on the surface chasing it.

"I was so excited when I saw the red tag, but trying to land it by myself was a bit of a challenge - I was glad to eventually get it in the boat!"

While you're with us, you can now receive updates straight to your inbox each Friday at 6am from the Katherine Times. To make sure you're up to date with all the news, sign up here