Carolan added SkyCity's move "made a mockery" of any attempt to quarantine Auckland from coronavirus.

The worker was employed at the casino as a dealer.

While recently travelling through Wuhan - the virus epicentre - and then on to Beijing, he contacted his boss saying he felt it was important he self-isolate when he returned to Auckland.

The worker emailed SkyCity management while in China requesting additional time off so he could quarantine himself for two weeks.

In the email, the worker states that "Wuhan city is the centre of the virus. It's pretty serious and scary".

If you have more information and would like to contact Michael Morrah in confidence, email MichaelMorrah@mediaworks.co.nz

In response, his manager agreed he could take leave. But when he returned to New Zealand, everything changed.

On January 30, the Ministry of Health advised people coming from Wuhan to self-isolate

On January 31, the worker returned to New Zealand.

On February 3, SkyCity emailed staff saying employees returning from China will be "required to self-isolate for 14 days".

But just a day after that advice, the worker was called up by his manager and told he could work, and so he did.

It's a move an Otago University School of Public Health professor slammed.

"I was really appalled to hear that this employer had asked the worker to return to work in less than 14 days of the self-isolation period," Professor Michael Baker told Newshub.

"Not only did that pose a risk to their co-workers, this person was also in the casino and dealt with the public."

Other SkyCity workers are also questioning why he was back on the job so soon.

"To see him at work was quite a surprise," SkyCity Casino supervisor Tina Barnett said.

"They just couldn't understand why the company would allow him to come back to work and not give him the 14 days isolation."

SkyCity told Newshub they were aware of a staff member returning to work 13 days after being in Wuhan.

"To date, we have not had any staff attending work who have presented with symptoms," the statement said.

Unite Union disputes SkyCity’s version of events, saying when the worker turned up for his shift, he’d been in Wuhan just 11 days earlier.

The Ministry of Health said SkyCity hadn't contacted them about the incident.

"I think it's contrary to the advice we would be giving, and I know the vast majority of employers will be supporting our overall efforts in this regard," the ministry's director-general of health Dr Ashley Bloomfield told Newshub.

The Ministry of Health advises people to contact Healthline on 0800 358 5453 for coronavirus advice.