New Zealand officials apologised to Australian Prime Minister Julia Gillard after a driver refused to let her on to a bus with other leaders during the Pacific Island's forum in Auckland last week and told her to get on the spouses bus.

A spokesman for Internal Affairs this afternoon confirmed the incident and said the apology was offered as soon as New Zealand officials were made aware of the incident.

The driver concerned had not been used again during the forum. He was employed by a company that ferried the leaders around Auckland under contract to the Department of Internal Affairs.

The incident happened when foreign leaders and their partners were being driven from Sky City Grand Hotel to the waterfront in two buses last Thursday.

Spouses travelled in a separate bus for security reasons.

A spokesman from Internal Affairs said the bus driver was immediately informed of his mistake and Ms Gillard got on the bus as planned.

She did not appear to take offence, however, an apology was offered and the department regretted that the incident occurred.

But it was not the only mix up during the forum. At the opening ceremony, the MC told leaders' spouses to "come up and meet your husbands".

Ms Gillard was heard joking with her partner Tim Mathieson about the slight and put her arm around him as they left.