An investigation has been launched after a Work and Income case manager is said to have "joked" to a Muslim client about taking a holiday in Christchurch.

Photo: RNZ / Rebekah Parsons-King

Ministry of Social Development client services manager Kay Read said if the alleged remarks are true, they are unacceptable.

The comment was apparently said to a Somali Muslim woman who had an appointment and it was overheard by the person who has made the allegation, Ms Read said.

The manager of the Auckland Work and Income office where the comment is said to have been made will be investigating the matter, but they have not yet identified the staff member who made the comment, she said.

"It's unacceptable, it's disturbing for us, I want to apologise for that, but we have zero tolerance for that type of comment, however it's made, in jest whatever, it is not acceptable to us as an organisation at all."

Ms Read said a general message has not been sent to staff as a result of this specific event, however following the Christchurch attacks staff were sent messages about zero tolerance and how to treat people.

The Ministry of Social Development has a number of Muslim staff who have been providing support in Christchurch, she said.

She said it was now necessary to investigate the allegation and get the full details before acting.

If is found to be true, the worker will have to undergo an employment process.