A spokesman for Auckland Airport said staff and guests inside the terminal at that time were considered casual contacts.
"The health and safety of staff and guests is always our foremost priority.
"In addition to the enhanced cleaning regime that has been in place since the outbreak of Covid-19, the domestic terminal was last night given a further deep clean.
"A fog machine was used to finely mist disinfectant and sanitiser across all surfaces in all public areas of the terminal likely to have been used by the infected traveller. This includes the food court, aviation security screening and gate lounge area."
Notifications were sent out to people who logged on with the Covid Tracer app at the affected businesses.
The incident was a reminder for people about the importance of using the Covid Tracer app, the Ministry of Health earlier said in a statement.