Prisoners have been isolated and babies put into quarantine at Auckland Region Women's Corrections Facility over fears of a measles outbreak.

On Tuesday night, Corrections informed Newshub there were concerns three female prisoners had been exposed to measles. They will remain isolated until their immunity status can be confirmed.

"We will continue to act on the advice of Auckland Regional Public Health Service and take all necessary steps to ensure the health and safety of our staff, prisoners and visitors at Auckland Region Women's Corrections Facility," Deputy National Commissioner Andy Milne told Newshub.

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These steps include:

• Restricting prisoner movements in and out of the unit where the prisoners were accommodated
• Ensuring only staff with confirmed immunity are working with the two isolated prisoners, and in the unit where the prisoners were accommodated
• Placing the Mother with Babies Unit at the site under quarantine as a precaution to ensure the health and wellbeing of all mothers and babies at the site
• Ensuring that staff are continuing to proactively monitor all prisoners on-site for any symptoms of infection
• Taking advice from Auckland Regional Public Health about vaccinations for our staff and prisoners

Auckland has had 944 confirmed cases of measles so far this year, and the number is continuing to rise.

"As you are aware, there have been a significant number of confirmed cases of measles in the Auckland community in recent weeks," Milne added.

"Because of this, we have been vigilant in ensuring that prisoners and staff are well informed about the symptoms of measles and how to prevent infection from spreading by supplying them with information from Health agencies, and will continue to reiterate the importance of this."