It took five rangers to pull the 15.5-foot beast from a permanent trap at Berry Springs — about half a mile downstream from the main waterhole, the Northern Territory News reports.
Croc catcher Tom Nichols said it was the biggest reptile rangers had caught in a trap this year.
"This is the largest crocodile we've removed from the area in the last four years and is also the largest crocodile we've removed from any of our traps in 2009," he said.
"It is unusual but every now and again we get one up (at Berry Springs)."
A Berry Springs ranger reported the find about 10am after checking the traps during his daily tour. The male creature had to be drugged before rangers removed him in just over an hour.
"He performed quite well actually for his size," Nichols said. "He could've given us a hard time but they're like humans. Some give you a hard time and others don't."
The find comes only weeks after the popular water holes had to be closed temporarily after bacteria counts in the pools had risen to abnormal levels. The croc was taken on the back of a trailer to the Darwin crocodile farm.
Nichols said the saltie was believed to have come through Darwin harbour before it was captured in the trap. To see a picture of the beast, visit news.com.au.