Five people are now in isolation after sharing a communion chalice with a man at St Mary's Catholic Church in Papakura who later tested positive for coronavirus.

The sixth coronavirus case in New Zealand shared communion with several others at a mass days before he tested positive.

Five parishioners sipped communion wine from the same chalice as the man at the morning service at St Mary's church in Papakura, south Auckland on Sunday March 8.

Parish priest Father Peter Murphy says those five worshippers isolated themselves after the news broke that the man had tested positive for Covid-19.

The man says he was not ill at the time and health officials have said the virus is mainly spread by those who are showing symptoms.

READ MORE:

* Coronavirus: Full coverage

* Coronavirus: New Zealand's sixth patient says he's feeling '100 per cent'

* Coronavirus: Father of New Zealand Steel employee with Covid-19 also being tested

* Tertiarty institutes abandon hongi at welcome ceremonies over coronavirus fears

* Cruise ship passengers could spread coronavirus

However, a cluster of cases in the United States was reportedly started by asymptomatic people.

LAWRENCE SMITH/STUFF Numbers at St Mary's fell sharply after it was revealed a man there had tested positive for coronavirus.

The Ministry of Health has said the man did everything right after falling ill.

He spoke exclusively to Stuff on Saturday night, on condition of anonymity, to reveal he had already fully recovered from the virus and was feeling "100 percent".

"Nothing to worry about there, she's all behind us," he said at the time.

The man, who is in his late 60s, returned from the US on Friday, March 6, on a flight from Houston to Auckland.

He had earlier been at a dinner at a New York raceway with people who had been in contact with American horseman John Brennan.

They were coughing and sneezing throughout, though Brennan himself was not in attendance.

LAWRENCE SMITH/STUFF Hand sanitiser was visible at St Marys on Monday.

Brennan later died of coronavirus aged 69, becoming the first fatality to the disease in New Jersey.

After arriving in New Zealand, the man felt fine and went to the Sunday morning mass.

There he served as a Eucharistic minister, a lay person who helps a priest to deliver consecrated bread and wine, the sacraments of holy communion.

ERIC GAILLARD A priest raises a communion chalice during a Catholic mass (file photo).

He was not showing symptoms then but was unwell within two days.

A coronavirus test administered by a well-protected doctor in the car park of a Papakura medical centre on March 12 returned a positive result the following evening.

Speaking again on Tuesday, the man reiterated his belief he would not have spread the virus because he was not sick during the service.

Fr Murphy confirmed five others shared wine from the same communion chalice as the man and defended his actions, as he was not sick at the time.

"He had no knowledge."

Those five were in self-isolation and being monitored by the Ministry of Health, Fr Murphy said.

Hand sanitiser was in use during the service and the people would not have sipped from the same location on the rim of the chalice, Fr Murphy said.

"We always turn the cup so you're not drinking from the same place."

Attendance at the church had plummeted after the Ministry of Health revealed its link to the sixth confirmed case, he said.

"The numbers are devastating. We're very low."

One employer had even stood down a parishioner of the church after learning he had been to the service, Fr Murphy said: "There was no need."