The Auckland Regional Public Health Service (ARPHS) said anyone who had been in the SkyCity complex, hotel, or stair challenge, as well as a nearby Mexican restaurant between May 22 and May 24, should check with their doctor that they had been immunised against measles.
People who could have been exposed to the virus and were not immunised should isolate themselves at home immediately until June 7, ARPHS said.
Medical officer of health Dr Richard Hoskins urged people to be cautious.
"The infected person had contact with a large number of people in Auckland while infectious," he said.
"It usually takes 10 to 14 days for someone who has caught measles to start showing symptoms. If anyone has been infected at the locations listed, they may start to develop symptoms from as soon as this weekend."
ARPHS said anyone who was worried they may have contracted measles should call their doctor first to avoid spreading the highly infectious disease, which could be caught just from sitting in the same room as someone infected.