The New Zealand dollar fell after the government stepped up measures to curb Auckland's bubbling housing market, stoking speculation the move would free up the Reserve Bank to reduce interest rates.
The kiwi dropped to 74.26 US cents at 8am in Wellington, from 74.72 cents at the New York close and 74.74 cents at 5pm in Wellington on Friday.
The trade-weighted index declined to 76.20 from 76.63 on Friday.
The government announced at the weekend that it will give the Inland Revenue Department an extra $29 million in this year's budget to chase property investors, tighten rules on investment gains and link transactions to IRD numbers while it assesses a withholding tax for foreigners, in a response to the growing fears about the pace of Auckland house price inflation.
Stepping up measures to tackle the housing market is seen as giving the Reserve Bank additional freedom to reduce interest rates as it eyes weaker dairy commodity prices and an elevated currency.