The New Zealand dollar fell to a fresh five-year low as investors exited riskier assets in favour of safe havens after Greeks look to have rejected austerity measures that would give them access to bailout money.
The kiwi touched 66.40 US cents, and was trading at 66.58 cents at 8am in Wellington, from 66.93 cents at the New York close and 67.23 cents in Wellington on Friday. The trade-weighted index slid to 70.25 from 70.61 on Friday.
The euro dropped after initial results showed Greeks voted on Sunday to reject the terms of a bailout with the country's creditors, raising concerns about the country's financial future.
With about 60 per cent of the votes counted, official figures show 61 per cent of Greeks rejected the bailout offer.
The uncertainty prompted investors to sell higher risk assets such as the kiwi and favour more liquid, stable currencies such as the US dollar and the yen and the perceived safety of government bonds.