It was election year, I was the leader of the opposition and I was as busy as a one-armed wallpaper hanger

Prime Minister Helen Clark

But now New Zealand's Sunday Star-Times newspaper has reported that Ms Clark's office commissioned a professional artist for the work, which Ms Clark then signed.

She told the newspaper she was only trying to be helpful.

"We thought it was a good cause and something was put in," she said.

She said she allowed the painting to be done by someone else because of "time pressures".

"It was election year, I was the leader of the opposition and I was as busy as a one-armed wallpaper hanger," she told the Sunday Star-Times.

'Joke'

Not everybody is so relaxed about the issue.

Auckland businessman Henry van Dijk - who paid NZ$1,000 (US$420) for the the fake prime ministerial work at the auction - said he was appalled.

"She never should have signed that painting if she didn't do it," he said.

"The painting is a joke. If it's not by her it's not worth $2 now," he said.

Ms Clark, who is also Minister of Arts, Culture and Heritage, has said she had offered to reimburse Mr Van Dijk his money.