A toddler from Hawke's Bay is the latest case of measles to be confirmed in the region.
The DHB's medical officer of health said health officials are working with family to see how the toddler caught the disease.
Dr Nicholas Jones said this case does not appear to be related to two other cases in the region.
He said it is unlikely there is any risk to the wider community as the toddler has been at home while infectious.
The latest case takes the total number of measles cases in the region to six.
And another measles case has also been confirmed in Queenstown, bringing the total number to 58 in the southern district.
The Australian Department of Health says two different Australian residents travelled to New Zealand while infectious.
One of the residents was in Queenstown from 25 September to 3 October.
The other resident was in Invercargill Airport at 6am for a flight to Perth via Auckland on 23 September.
Anyone who thinks they might have been exposed should watch out for symptoms and isolate themselves immediately if they start to get sick.
Meanwhile, health authorities are warning that people at a national secondary schools basketball tournament in Palmerston North this week may have been infected with measles.
A person at the tournament from Monday to Wednesday has been confirmed to have measles, and is now in isolation.
The Midcentral District Health Board's medical officer, Rob Weir, said anyone not immune to measles who was at the tournament should stay in isolation to prevent the further spread of the disease.
Dr Weir says symptoms should show up between 7-16 October.
Hundreds of teenagers from throughout the country are attending the tournament, hosted at the Fly Palmy Arena.