The Human Rights Commission has received a complaint of alleged unlawful discrimination on the grounds of religion on the wearing of kirpan at New Zealand Cricket World Cup venues.
A commission spokeswoman said the complaint was being assessed and referred to the parties under its confidential dispute resolution process.
Seven Sikh cricket fans were refused entry to Eden Park to watch a World Cup match between India and Zimbabwe last Saturday because they were wearing kirpans.
The kirpan is a ceremonial sword or dagger carried by Sikhs for religious purposes, but is considered to be a weapon by the International Cricket Council.
Prime Minister John Key yesterday said the ICC rightly set the rules of what could be brought into venues but he believed it was wrong in barring Sikh fans from wearing kirpans.
In recent weeks, he had met members of the Sikh community and was sympathetic to their position.
"My understanding of the kirpan is it is for the most part very small, it's a blunt instrument," Mr Key said.
"And actually, if you want to make the case that someone could cause harm with that, they're probably much more likely to be able to cause harm with anything else you can get at the grounds, including a wine bottle or something else."
National Sikh list MP Kanwaljit Singh Bakshi said he also wore a kirpan to the match, but was not stopped from entering the stadium.
The Supreme Sikh Council yesterday said it wanted greater consistency from the ICC about who it lets into cricket stadiums.
An Australian-based Indian online site, singhstation.net, also reported that Sikh fans wearing kirpan were allowed into the Adelaide Oval for the India-Pakistan match last month.
"If the kirpan is banned then security should be checking everyone including MPs and officials, and not just targeting a selected few," said council chairman Daljit Singh.
Mr Singh estimated there were about 250 Sikh fans with kirpans who had been allowed into Eden Park last Saturday, including Mr Bakshi.
"There are about 500 people in our community who are holding tickets for the semifinals. Must they depend on luck to see if they can get in?" he asked.
Mr Singh said the kirpan was one of five articles of faith to be worn by baptised Sikhs at all times and cannot be removed.
Yesterday, the Cricket World Cup organising committee said it had no further comment to make on this issue except for a point of clarification.
"Despite every effort being made to enforce our terms and conditions of entry, and it being the responsibility of patrons to adhere to them, it is not inconceivable that, being concealed, some patrons may have brought kirpans into World Cup venues," said committee spokesman Philip Clark.
The kirpan is usually worn beneath clothing and, although possessing one is not illegal, Mr Clark had earlier said the ICC prohibited entry to the venue of any type of knife, and that rule extended to kirpans.
Ethnic Communities Minister Peseta Sam Lotu-Iiga, who was with Mr Bakshi at the match, said: "Balancing the need for security and safety at ICC matches with religious beliefs of the Sikh community is not easy.
"We need to keep talking to the Sikh community about how both sides can be accommodated."
Mr Bakshi said he was not asked if he was wearing a "symbolic" kirpan around his neck and was not aware of the ICC's "no knife, no kirpan" policy.
He said one possible compromise could be for Sikh cricket fans to wear smaller kirpans, rather than carry the usual ceremonial sized ones.
AUT University Professor of Diversity Edwina Pio said it was pertinent to note that not all Sikhs carried a kirpan, unless they were baptised, and that airlines also did not allow kirpans on board.
"Balancing security with religious freedom in an age where terrorism and individual rights abound is the crux of the issue."
It was perhaps wiser to keep the kirpans in safe custody, she said.
Matter of faith •A kirpan is a religious sword or dagger carried by baptised Sikhs bound by a religious commandment by Sikh guru Gobind Singh in 1699. •The kirpan was formally included as a mandatory article of faith making it a duty for Sikhs to be able to defend themselves and others from oppression. •In 2008, Sikh leaders chose not to attend an interfaith meeting with Pope Benedict XVI in Washington rather than remove the kirpan.