Thousands of Auckland women appear to have received texts sent in error reminding them of breast screening appointments.
A woman told the Herald she received the text from BreastScreen Aotearoa today, despite not being due to have a mammogram.
BreastScreen Aotearoa is New Zealand's free national breast screening programme for women aged between 45 and 69.
The text - which included her private health number - came with an 0800 contact number.
When the woman called it the operator told her every woman on the Auckland breast screen register had received a text to attend an appointment.
"Lines are chock-a-block."
In a statement BreastScreen Auckland Limited's board of directors apologised for the mistake which saw 50,000 women in Auckland central receive the text.
"This occurred as the result of human error. BreastScreen Auckland Limited is further investigating."
Albert Eden Local Board deputy chairwoman Glenda Fryer also received the text, as did six others at a lunch she was at today.
None of the group were due to have their mammograms and so assumed it was a mistake.
By mid this afternoon a voice message on the Auckland BreastScreen phone number alerted callers that a text message had been sent in error and should be ignored. An apology text would follow soon, according to the voice message.
A Ministry of Health spokesman said the texts were not the result of a hack, but he did not have any further information.