According to Bill Emmott, writing in last Thursday's Times, the Italian prime minister imported the phrase bunga-bunga from Libya.
But the word has also been spotted (without the repetition) Down Under. In 1898 Australian dictionary-maker E. E. Morris noted Bunga or Bungy, a New Zealand settlers' corruption of the Maori word pung, a variety of tree fern.
By 1926 Trans. N.Z. noted that ‘bunger’ was now fortunately seldom heard for ‘ponga’.
