The company running next year's Rugby World Cup says some customers have been mistakenly charged twice for their tickets.
It says this was caused by an, as yet, unspecified technical error.
Rugby New Zealand 2011 Ltd says the problem came to its attention on Wednesday and was fixed within a day.
It says the charges have been reversed and this process would take four to five working days.
The company is not saying how many people were affected by the overcharging, except it was a small number.
