Labour's ethnic communities spokesman Phil Goff is calling for the Government to clarify where and when Sikhs can wear a kirpan.
The Mt Roskill MP said there needed to be legislation on the matter to prevent any future confusion.
Seven Sikh cricket fans were barred from entering Eden Park to watch India play Zimbabwe in a Cricket World Cup match on Saturday because they were wearing kirpans.
The kirpan is a ceremonial sword or dagger carried by baptised Sikhs for religious purposes. To possess one is not unlawful in New Zealand, but the International Cricket Council considers the kirpan a weapon and bars it from venues.
Yesterday, Prime Minister John Key said he felt the ICC was wrong in barring Sikh fans from wearing kirpans at World Cup matches. He also signalled the Government could change Civil Aviation Authority rules to allow kirpans to be taken on flights.
It is legal to wear a kirpan in New Zealand, but not on flights.
Mr Goff said while he welcomed the Prime Minister's commitment to ensure Sikhs were not discriminated against in being prevented from wearing the kirpan in public, more weight would attach to legislation allowing it than a statement at a press conference.
"In other countries, such as India, Canada, the UK and some Australian states, legislation has been passed recognising this right," Mr Goff said.
"Safety considerations, of course, have to be taken into account, but the experience in other jurisdictions appears to have been that the right by law to carry the kirpan has not caused problems."
A complaint had been lodged with the Human Rights Commission for alleged unlawful discrimination on the grounds of religion on the wearing of kirpans at New Zealand Cricket World Cup venues.
Arunjeev Singh, general secretary of the Voluntary Law Association of India NZ, said the Sikh kirpan was not "a blunt instrument" as claimed by Mr Key. "It is a fact that in Sikh religion, a kirpan is a weapon for self defence," Mr Singh said. "The practice of keeping a kirpan ... is not only symbolic, it is for a purpose, to use for only self defence. It is certainly capable of causing grievous bodily harm."
Justice Minister Amy Adams said: "I recognise that it's a genuine issue for the Sikh community, but of course we also have to balance public safety considerations. I'm open to considering changes to legislation in the future and would be happy to do so on a bi-partisan basis."