The Ministry of Health is advising anyone who stayed overnight on Saturday (December 4) in the Green Lake Hut to self-isolate and get tested immediately.
Officials regard the remote wilderness setting as a high-risk for anyone in the same venue, the latest locations of interest show.
A close contact of an infected person arrived at the hut on Saturday at 7pm and left the following morning at 8am, the ministry said.
Green Lake Hut is a three- to six-hour walk on the Green Lake Track, which is considered an advanced or challenging hike.
According to the DoC website it has 12-bunk beds and bookings are not required, operating on a first come, first served basis.
Earlier this month it was announced that from December 15, all hikers over the age of 12 will have to be fully vaccinated against Covid to stay in DoC accommodation and campsites.
"All DoC campgrounds and huts will only be open to those who are fully vaccinated. When booking, visitors will be required to confirm they and all others in their group are fully vaccinated," DoC Heritage and Visitors director Steve Taylor had said.
"Hut wardens and camp hosts are regularly on site and will be checking for vaccination status."
In more remote regions and huts without wardens there would be spot checks for campers' My Covid Pass.
