Waikato Hospital's apologised to dozens of patients for a privacy breach which occurred last month

Health NZ Waikato has contacted 38 people who participated in health screening services, and had related correspondence incorrectly delivered to two residential addresses.

The letters should've gone to the relevant medical centre.

The letters were meant to be sent to medical centres in batches, with patient names and addresses included below the address of the medical centre.

When the letter moved in its envelope, the wrong address showed through the window - and they were wrongly sent to two residential addresses.

One more person caught up in the privacy breach has yet to be contacted.