While NSW police on Friday morning ruled it out, Dominic Perrottet said the organisers of the camp should face the consequences.
NSW Health has ordered Hillsong immediately stop singing and dancing at the summer camp in Newcastle, after videos emerged showing hundreds of attendees without masks, singing and dancing inside a large tent while a band performed onstage.
The camp began days after changes to public health orders took effect, banning singing and dancing at music festivals and forcing the cancellation of music events like the Tamworth Country Music Festival and the Grapevine Gathering in the Hunter Valley.
Singing and dancing at large events presents a high risk of COVID-19 transmission, Chief Health Officer Dr Kerry Chant said, amidst an outbreak which has seen the state record tens of thousands of cases a day.
The order does not apply to religious services, but it does apply to major recreation facilities, and the event is "clearly in breach of both the spirit and intent of the order" Health Minister Brad Hazzard said.
Mr Perrottet on Friday said the Mr Hazzard had advised him the legal team had determined Hillsong had breached the public health orders.
"If the legal teams believe that it was in breach of the public health order, then my expectation would be that a fine would be issued."
He joined a chorus of Australian music acts in saying he was shocked and outraged to see the footage.
"I fully understand how outraged they would be, in circumstances where they're doing the right thing and others are doing the wrong thing.
"Even if technically it was within the rules, it certainly wasn't in the spirit of the rules.
"If we have to tighten loopholes, we will."
NSW Police earlier on Friday said the church will not be fined, and police will instead liaise with organisers "to ensure future compliance".
In a statement, Hillsong defended the event, saying it is "not similar to a musical festival in any way".
The summer camps involve primarily outdoor recreational activities, with outdoor Christian services only a "small part" of the program and singing a small part of each service.
"A video circulating on social media (on Thursday) reflects a few minutes of this part of the program," it said.
"We follow strict COVID procedures and adhere to government guidelines."
But Newcastle MP Tim Crakanthorp accused organisers of "pure arrogance", the ABC reports.
"This is an absolute slap in the face to the people that have lost work as a result of the current rules," he said.
That's a sentiment echoed by artists on social media.
"There are rules in place that just aren't right," Sydney pop rock duo Lime Cordiale wrote on social media.
"Festivals, clubs and pubs are closed whilst Hillsong are getting close and sweaty... confusing?"
Australian acts including Jack River, Illy and Odette also criticised the event as demonstrating a double standard, with Brisbane band Ball Park Music describing it as "just heartbreaking for everyone in our industry".