The attack happened at 10am this morning approximately 206 kilometres south west of Yirrkala.
Police said they did not know the identity of the victim.
The last fatal crocodile attack in Australia was October last year when a 79-year-old dementia patient was killed after wandering from a nursing home at Port Douglas in Queensland state. Local wildlife rangers killed the crocodile.
A woman has been attacked and taken by a crocodile in remote Arnhem Land in the Northern Territory. It is not yet known if her body has been located or if a search is underway.
The circumstances surrounding the incident have not been confirmed due to the remoteness of the location and difficulty relaying information.
It took police three hours to get to the billabong the group of seven women and children were at in east Arnem land today, near Gan Gan, about 128m south west of Yirrkala.
"NT WorkSafe has commenced an investigation into the incident", it said in a statement.
CareFlight, which is usually tasked to assist with medical situations in remote locations, at this stage is not attending the scene.