Health officials have admitted failing to pass on a complaint of fraud made against the largest Maori service for intellectually disabled people.
An independent forensic audit by PwC begins on Monday into Te Roopu Taurima o Manukau after allegations of misspending raised by former staff and by New Zealand First leader Winston Peters.
A senior official at the Ministry of Health, Michael Hundleby, now says its fraud hotline failed to pass on to previous auditors an anonymous allegation of fraud made in December last year.
"We recorded details of that but unfortunately due to human error and miscommunication, those details were not passed on to the auditors that were undertaking an audit of Te Roopu."
Mr Hundleby said this call included names and details of alleged activities, but would not discuss these ahead of a new audit starting next week.
Two previous audits this year run by the ministry raised no concerns about financial practices.
The ministry said it knows who among its own staff made the mistake and would contract out its hotline service to Crimestoppers, already used by several other government agencies.