Coronavirus: Prime Minister Jacinda Ardern scolds Crusaders for lockdown training breach

Prime Minister Jacinda Ardern has warned "no-one can be exempt", scolding Crusaders rugby players for breaking lockdown rules in an impromptu training session on Monday.

The three-time Super Rugby champions have been under fire, after Newshub filmed several of their roster at Christchurch's Melvern Park, mixing at least two 'bubbles' under coronavirus alert conditions.

All Blacks first-five Richie Mo'unga was the most readily identifiable culprit, and the actions have been condemned by Crusaders leadership, NZ Rugby and now the nation's leader.

"It flies directly in the face of the advice we are giving," Ardern told her daily COVID-19 media briefing.

"I would just say to people in positions like that, we are relying on everyone to role-model the behaviour we need right now. We are all in this together.

"I'm really asking for leaders in our sporting codes to join us in this, because we can't do it alone. No-one can be exempt." 

Earlier in the briefing, Ardern had been called to task over her decision to demote, but not to sack Health Minister David Clark for flouting lockdown rules, when he was caught driving 20k from home for a beach walk, instead of 'staying local'.

Just hours after Mo'unga announced he and wife Sophie were expecting their first baby - a daughter - he was slammed on the same social media post for possibly endangering his family by possibly bringing the virus into their house.

Director-General of Health Dr Ashley Bloomfield stopped short of confirming that risk, but offered some sage advice for Mo'unga.

"I can't comment on this specific situation, but he may well be in as much trouble at home as he is in the media," quipped Dr Blomfield.    

Police confirm they won't be taking any action over incident.

"Police have not had reason to speak with the Crusaders on this matter and the incident was not reported to Police.

"Police are taking an education and encouragement approach to the enforcement of the Alert Level 4 restrictions. We understand this matter had been addressed by Crusaders management."

On Monday morning, Mo'unga posted an Instagram apology for the session, which he insisted was "coincidence".

"This was not an organised training," he said. "There were no communications the night before, saying we should all get together and train at the park together.

"It was by coincidence that I rocked up and they were there training, just finishing up their session.

"As I finished one of my running sessions, the ball had been kicked over and instinctively, I picked the ball up and threw it back to them.

"That was the only interaction I had with them, apart from talking. It was something that was so instinctive for me to do, to throw the ball back to them, I didn't think twice about it. 

"It happened so fast, and I've learnt with this whole thing that I need to be more careful and I will be more careful."

NZ Rugby chief executive Mark Robinson condemned the interaction as "unacceptable" under the COVID-19 lockdown.