St Patrick's Cathedral in Auckland is asking its parishioners to attend mass at other churches or consider less popular mass sessions in a bid to bring congregation numbers to under 500.
In the wake of the coronavirus Covid-19 outbreak the Government has banned all gatherings of 500 people or more, including those of a religious and cultural nature.
St Patrick's has four masses every Sunday, and the 11am mass usually gets the largest attendees sometimes in excess of 1000 and the 7pm also usually exceeds 500.
"In view of the constraints that are now in place we are advising parishioners and mass goers to come to one of the other three Sunday Masses, or to go to other parishes where congregations are not so large," said Father Peter Tipene, the cathedral's dean.
"Other parishes in the diocese that have particularly large congregations will also advise their congregations to spread their attendance across the Masses or to visit a smaller neighbouring parish."
A man who attended mass at St Mary in East St, Papakura on March 8 was later tested positive for Covid-19.
Those who were at the service that morning have been contacted and a majority were told they didn't need to self-isolate because they didn't come into close contact with the man.
Tipene said it was noticeable that numbers were down last Sunday at mass.
"We are advising our parishioners not to buy into a pandemic of fear, and to take heart from the encouragement that our faith provides," Tipene said.
The mass is the core of our Catholic identity and our source and summit."
However, he asked those who were ill, self isolating or who thought attending mass could put others at risk should stay home.
Jacklyn Tiong, a parishioner and altar server at St Patrick's, said she saw the cathedral's notice on its Facebook page and would consider attending a smaller church this weekend.
"I think doing this is for my own good and for the good of all the other churchgoers," Tiong said.
"I try to keep to the rules of social distancing even in church, but that won't be possible if the mass is too crowded."
Following Ministry of Health advice, the Catholic Church throughout New Zealand has stopped shared holy water from fonts, communion on the tongue or wine from the chalice.
The practice of shaking hands at the Sign of Peace or joining hands during the Lord's Prayer is also stopped.
Catholic Bishop of Auckland Patrick Dunn has called on Catholics to be vigilant but to not be overly concerned about going to mass.
Dunn said the chance of catching any illness at mass is very low if people heeded the standard health advice to wash hands, avoid close contact with anyone who is ill and stay home if feeling unwell.