The Ministry of Health has this morning officially confirmed a fourth positive test for coronavirus Covid-19 in New Zealand.
The result came from a New Zealand citizen, a man in his 30s, who is the partner of the second case confirmed on Wednesday.
New Zealand Steel has confirmed that the man is an employee at the company's Glenbrook plant.
"We are pleased to advise that the affected employee has confirmed that they are not seriously ill and are in isolation at home," CEO Gretta Stephens said in a statement.
"We are working directly with the Ministry of Health, and the practises we have put in place are consistent with their recommendations.
"This includes contacting and working with those employees who have had primary contact with this employee.
"We can confirm that the affected employee has not been in any plant operating areas or the cafeteria."
The man had been with his partner in northern Italy, and they arrived in Auckland from Singapore on February 25 on Air New Zealand flight NZ0283.
On Monday, they flew to Palmerston North on flight NZ5103 and then back to Auckland on flight NZ8114.
Anyone who believes they may have been in contact with the couple is urged to contact Healthline by phoning 0800 358 5453.
The ministry said contact tracing is already underway and that some people who had been in close contact with the couple are already in isolation.
The couple's two children, who attend Westlake Boys and Westlake Girls high schools in Auckland's North Shore, are also isolating themselves but are not showing symptoms, according to the Auckland Regional Public Health Service.
Dr Ashley Bloomfield of the Ministry of Health earlier this week discouraged people from making hurtful online comments about those diagnosed with COVID-19, as it could discourage people from coming forward.
His comments came after hurtful comments were made online about the confirmed cases by "keyboard warriors".
The couple's children were not in Italy and the self-isolation is being taken as a precaution, with the schools alerted.