Police Minister Judith Collins says a stunt staged by the Sunday Star Times newspaper, involving people masquerading as terrorists at Super 14 rugby games, was incredibly stupid.
The newspaper has defending its activities as a matter of significant public interest.
Ms Collins says the newspaper commissioned people to carry fake explosives to try to gain access to restricted areas at Super 14 matches in Hamilton and Christchurch last weekend.
She says in some cases they were successful.
But she says the stunt had the potential to result in games being cancelled and stadiums evacuated, which could have led to people being hurt if there was panic.
Police spokesperson Jon Neilson says officers have spoken to the paper's editor, but at this stage, there's no evidence of an offence being committed
However, he says, police do not approve of such activities which have the potential to cause disruption.
Waikato Chiefs chief executive Gary Dawson says it was a stupid pointless stunt with potentially dire consequences, if a lot of people had had to be evacuated in a short time.
Mr Dawson says he's satisfied the stadium has appropriate security measures in place.
However, fans going to Waikato Stadium in Hamilton will be more thoroughly searched after the incident.
Stadium manager Ollie Te Ua says the first he knew about what happened was when the reporter rang earlier this week.
The Sunday Star Times says the Minister has grossly overstated its actions.
In a written statement, the paper's editor Mitchell Murphy says the Minister never sought to verify any information with the paper.
He says the investigation is a matter of significant public interest and has been well planned and carefully considered.
The paper says it has been discussing its investigations openly with police and offered to assist them in fixing flaws exposed in security levels.