A census collector who mistakenly handed out an already complete form to another household has apologised for the privacy breach.
The form was one of six million already handed out ahead of today's census.
General Manager Carol Slappendel said the Privacy Commissioner's guidelines on how to deal with the breach were being followed.
"(It) involved one individual form, so it's very contained and it was accidental, it was a case of human error and the collector's very, very sorry."
Ms Slappendel said it was a case of human error and the form had been recovered.