An Australian news broadcast has made an embarrassing gaffe after accidentally using a New Zealand flag on a story about Australia Day.

The Brisbane edition of 9 News used an image of the wrong flag while the newsreader introduced a story on the national holiday.

Eagle eyed viewers were quick to notice the error and posted a picture of the broadcast to Reddit, captioning the image "'Australia' Day".

Some Reddit users didn't see too much of a problem with the error, saying New Zealand was supposed to be part of Australia.

"NZ has always been a renegade state that needs to be reclaimed," one user commented.

"The average Australian wouldn't spot the difference," another said.

Over on Facebook the video was uploaded without the introduction but that didn't stop several commenters from sharing images of it as it was broadcast.