The staff member tested negative to the virus in New Zealand on 18 November but on arrival in Shanghai on 22 November returned a positive test.
Air New Zealand said the person was well and had no symptoms of Covid-19 - all other crew have returned negative results.
It said the positive case would remain in isolation while Air New Zealand and the Ministry of Health worked with Chinese authorities to bring the person home.
"Operating crew on layover in China go into a managed isolation hotel as a standard procedure.
"The crew will remain in isolation while we work with Chinese authorities, New Zealand Ministry of Health and New Zealand Ministry of Foreign Affairs and Trade to make arrangements for their safe return home," an Air New Zealand spokesman said.
When they returned to New Zealand the crew would follow the direction of the ministry around isolation and further testing, Air New Zealand said.