A small crocodile has been rescued after wandering on to a busy highway about 10 kilometres from Darwin's central business district.

Northern Territory Police say the metre-long crocodile was first sighted near a service station on the Stuart Highway at suburban Berrimah.

Watch Commander Vicki Koum says police were called to the scene at about 3:00am.

"It was a young child who actually saw the crocodile," she said.

"She was with her mum in the car and she spotted him."

Police officers found the crocodile too aggressive to handle, so Parks and Wildlife rangers had to be brought in.

Watch Commander Koum says it was captured before traffic became too busy.

"He was a bit snappy but he was taken away safely, unharmed, and nor was any one else," she said.

Police believe the croc may have been a resident of a local tourist attraction.

"We've got the Crocodylus Park down there, so maybe he's an escapee," Watch Commander Koum said.