Labour MP Shane Jones has revealed a prominent National Party supporter helped fund his bid for the Labour leadership last year.
Sir Wira Gardiner, who is married to Cabinet minister Hekia Parata, put $1000 towards Mr Jones' campaign and did not tell his wife until this weekend.
Mr Jones said that while he would not call Sir Wira a friend, he has known him a long time and they sat together on the Fisheries Commission. He said Sir Wira has always encouraged Maori to stand up for leadership positions and his motives were genuine.
The MP said he also received several thousand dollars from New Zealand Oil and Gas board member Rodger Finlay.
"They contributed because they felt that I had something to offer in the leadership campaign. I was the underdog - that term proved to be brutally true when the final vote came out."
Prime Minister John Key said on Tuesday he was amazed to hear that Sir Wira had helped fund Mr Jones' leadership bid, as was Ms Parata.
"Well, you know at the end of the day, he's free to do what he wants to do. Look, I think it's literally an issue of Maoridom.
"Wira rang me last night, he said he's known him for 30 years. It's nothing personal ... if there was going to be a new leader of the Labour Party, he'd prefer it was a Maori. Feels like a waste of a thousand bucks to me."
Donations to the three Labour candidates vying for leadership in September 2013 were to stay confidential, but it later emerged that amounts over $500 had to be disclosed. David Cunliffe named three of his donors and returned money to two others. Grant Robertson, the other MP to run for the leadership, said he had no donations of that size to declare.
Sir Wira did not return Radio New Zealand's calls on Tuesday.