The inmates escaped from a work release center at the Berrimah Jail and then came back after a few hours.
"It would appear that a couple of prisoners have jumped the fence but returned," a spokesman for NT Department of Correctional Services told the ABC.
The prisoners allegedly hopped the center's fence and then met up with partners on the outside.
Guards discovered five drunken prisoners fighting over a phone and figured out what had happened. It's possible that this is not the first time the prisoners have escaped and returned.
Five cellphones, two empty bottles of booze and a small quantity of a substance, believed to be marijuana, was discovered during a search of the center.
The inmates are being held in a maximum security section of the prison and authorities are continuing to investigate what exactly happened.