New Zealand First leader Winston Peters will face questions about a donation he received from a Monaco-based businessman during the party's annual conference on Saturday.
Mr Peters had denied newspaper reports that Owen Glenn gave money to the party, but on Friday revealed that $100,000 was paid in 2006 to cover his legal costs incurred during the Tauranga electoral petition at the last election.
Earlier in the week, Mr Peters had strenuously denied that New Zealand First received any donation from Mr Glenn.
He says the donation was made through his lawyer Brian Henry, and he was only told about it on Friday.
Mr Peters says Mr Henry has been involved with fundraising money to meet the costs of litigation involving politicians and had a strict policy of never disclosing the source to the politicians involved. That policy was only broken after fresh publicity at the weekend over Mr Glenn.
Mr Henry, who has worked for Mr Peters since 1991, says he revealed the source of the money in order to protect the donor's reputation.
Mr Peters says the key issue now is planning for the election campaign.