The man was at Turoa skifield on Sunday, August 9. He was well at the time.
He is considered to be infectious from 48 hours before onset, which means from 2pm on Sunday.
The man spent some time skiing on the mountain earlier that day.
Whanganui DHB says the overall risk to other skiers is considered to be very low as the case was outside the infectious period at this time.
He visited the Alpine cafe between 1.45pm and 3pm, which falls just within the start of his infectious period.
Anyone who was in the café at this time is at slightly greater risk of contracting Covid-19, though still low.
The DHB said there was no need for people to isolate themselves but asked that people remain vigilant about possible symptoms.
If they do develop Covid-19 symptoms, the Ministry of Health advice is to isolate from others and get tested as soon as possible.
Ruapehu Alpine Lifts (RAL) CEO Jono Dean said it was advised by Whanganui DHB on Friday that a positive case from the Auckland cluster visited Tūroa ski field.
Following this advice two RAL staff self-isolated and were tested for Covid-19.
They have received their results and are negative for COVID-19.
Public Health officials have advised that the interactions any of our staff have had with this person are not considered to meet the definition of a close contact.
The person also visited Whakapapa Ski Area on Saturday, August 8 but was considered pre-symptomatic and so unlikely to be infectious at this time.
Because of this the DHB have advised that there is no cause for concern or action beyond current Level 2 protocols.
Deep cleaning and thorough cleaning routines are also being done and both Turoa and Whakapapa ski fields remain open.
Dean said RAL had direct instructions from the Ministry of Health and Wanganui DHB that if its crew were not symptomatic then they were safe to be at work.
"Therefore we remain confident that we are following best practice.
"We will be encouraging all staff to wear masks towards the same goal of preventing any possible spread."
