Nicole Green was in managed isolation at Naumi Hotel at Auckland Airport and due to leave on June 27 - but had to be tested again on day 14.
She says she contacted authorities asking when she could leave because her day 12 results hadn't been returned.
Green says she was told her test had been lost and she wasn't in the database.
A Northern Region DHBs spokesperson disputes the test was missing, but told the Herald her day 12 test hadn't been received by the laboratory for processing.
