They had taken a charter flight home to Auckland on September 11, after finishing their managed isolation period in Christchurch.
The Ministry of Health said the family visited the Taupō Tandem Skydiving base at Taupō Airport on September 19, between 2pm-3.30pm.
Taupō Tandem Skydiving chief executive Hamish Funnell said the skydiving instructor was wearing a face covering and a full-face helmet, and the tandem diver who later tested positive for Covid-19 was wearing a high-velocity-style face covering.
"As a precaution, the person he [the positive case] jumped with is considered a close contact and is in isolation for two weeks. Everybody else who was a casual contact in the aircraft is in isolation until they get a negative result."
Funnell said there were about 12 people onboard the aircraft, all wearing face coverings.
He said the Ministry of Health had contacted the other passengers, and he had looked through security camera footage to determine any other contacts.
Funnell said the base was closed for a deep clean, as a precaution, and all staff who worked on Saturday are getting tested.
"I'll be relieved in a couple of days when the Ministry of Health come back and tell us that all our staff are negative."
Funnell said business had been slow.
"All tourism operators are struggling at the moment. New Zealand domestic tourists have been fantastic, it's not an ideal situation for us [to close], but it's the right thing to do."