The Ministry of Education is the latest government ministry to be involved with an email privacy breach after a letter was sent to the wrong person.
The Ministry's acting chief executive, Peter Hughes, says a staff member realised on Friday that they had attached the wrong letter to an email.
The letter was advising a family that their child could be enrolled at a special needs residential school.
Mr Hughes says staff spoke to the person who received the letter and asked them to delete it, and have also emailed them a letter, but have not yet had a response.
Ministry staff have visited the family the letter was intended for on Saturday morning and apologised, Mr Hughes says.
A review of information security and privacy within the Ministry of Education began on Monday.
The privacy breach is the latest in a string of email breaches.
Last month, Earthquake Recovery Minister Gerry Brownlee had the Earthquake Commission's external email system shut down after a spreadsheet containing 2200 names and information about $23 million of cheques that not had been cashed were wrongly sent to a Christchurch man.
Earlier an email from the Commission, containing details of 83,000 Canterbury claimants, was mistakenly sent to an insurance advocacy company.
And an email was sent from the Ministry for the Environment in March, revealing the private email addresses of 147 people.
In August 2011, details of more than 6000 ACC clients were mistakenly sent to Auckland claimant Bronwyn Pullar, resulting in the resignations of ACC minister Nick Smith, ACC chair, John Judge, two directors and chief executive Ralph Stewart.