"At the end of the day if someone's removed from a bar it should be because they're underage or they're intoxicated. Ethnicity's got nothing do with it."
The police had operational responsibility and the Government could not direct them.
"But I was frankly quite surprised it's happening."
Asked if the law was racist, Mr Key said: "It feels a bit that way."
He said the law may need to be changed over time.
Maori Party co-leader Pita Sharples said he was disappointed police had announced they would be using Maori Wardens.
"Maori Wardens have their own authority, and while they may work with the police and have some training and share some facilities ... the reality is Maori Wardens are stand-alone people."
The law was "a little bit historic" and that was why it was being reviewed, he said.
Green Party co-leader Metiria Turei said the law should have been repealed many years ago.
"If the police and the council are wanting to use the Maori Wardens in order to target Maori during the Rugby World Cup, then that is a problem and they need to come and out clarify whether that's the case, because that's discrimination."
Ms Turei said if police wanted the wardens for community policing, then that was what they were there for.
"But they should respect the wardens and make sure that they are properly resourced to do the job."
- NZPA
