The police are investigating after a postal bag with hundreds of letters inside was found at a rental property in Wellington.
New Zealand Post says the bag belonged to a postie who was dismissed in 2008 for theft and non-delivery of other bags.
The postal service says the bag, with 379 mail items, was found earlier this year and contained letters for about 10 streets in the suburb of Johnsonville.
It says it didn't know the postie kept the bag when the worker was sacked.
New Zealand Post says it has sent letters of apology to residents and is returning the letters.
It says it apologies for any distress and says it takes situations like this very seriously.
Meanwhile, a Queenstown postie who pleaded guilty to hoarding mail is expected to be sentenced on 8 April.