Director-General of Health Dr Ashley Bloomfield has tested positive for COVID-19, the Ministry of Health says.
He is currently in Geneva, Switzerland for the World Health Assembly.
"Dr Bloomfield tested positive on Thursday and is now self-isolating in Geneva. This will mean a delay in his return to New Zealand. He is experiencing mild symptoms," a Ministry of Health statement says.
"Dr Bloomfield was attending the Assembly with Health Minister Andrew Little, who left Geneva earlier this week. Both were following all appropriate health precautions."
Dr Bloomfield, who will retire from the top health role in July, has been the face of the ministry's response to the COVID-19 pandemic. He has featured alongside the Prime Minister and ministers at press conferences over the past two years.
"The DG role is complex and challenging at any time and, with a one in 100 years pandemic, the last two years have been particularly challenging and intense," he said when his retirement from the role was announced.
"I've done everything I set out to do when I came into the role. I would not have been able to do this without the support of many highly committed and talented people in the Ministry and across the wider health system."
His positive diagnosis comes a little under two weeks since Prime Minister Jacinda Ardern tested positive for the illness. She was already isolating as her partner Clarke Gayford had become infected.
As of Thursday, there were 50,171 active cases of COVID-19 in New Zealand.