The New Zealand dollar gained after the Federal Bureau of Investigation said it was investigating more emails as part of a probe into Hillary Clinton's use of private email system, potentially denting her US presidential race.

The kiwi traded at 71.46 US cents as at 8am in Wellington after reaching as high as 71.67 cents in late New York trading and from 71.36 cents in Asia at the end of last week. The trade-weighted index edged up to 77.14 from 77.07.

US stocks fell and the greenback declined against most major currencies after FBI director James Comey said in a letter to US lawmakers that the agency was looking into whether the additional emails contained classified information. The email issue has dogged Clinton's campaign and the new twist stoked speculation she may not be a certainty to win as the market has been expecting, with Donald Trump seen as providing certainty.

"This was seen to increase the chance of a Trump victory, the risk of some chaotic market conditions post-election and therefore a slightly reduced the chance of the Fed tightening ahead," said Jason Wong, currency strategist at Bank of New Zealand.


The US election is on November 8. Ahead of that, the Federal Open Market Committee holds its two-day meeting this week, with no change expected in interest rates until December. Figures on Friday showed US gross domestic product rose at a 2.9 per cent annual rate in the third quarter, following a 1.4 per cent pace in the second quarter, beating estimates, but analysts said the underlying picture of the world's biggest economy was weaker than the headline number implied.

US labour market data rounds out the week, with economists polled by Reuters seeing a rise in nonfarm payrolls to 175,000 in October, from 156,000 the previous month. At home, labour market data is due out on Wednesday that will show whether any wage inflation is emerging ahead of the Reserve Bank's monetary policy statement next month, while the Reserve Bank's survey of expectations will show whether inflation is emerging and whether expectations of low inflation are becoming entrenched.

The kiwi traded at 58.81 British pence from 58.74 pence in New York on Friday. It slipped to 4.8421 yuan from 4.8516 yuan and dropped to 65.01 euro cents from 65.14 cents. The kiwi fell to 94.06 Australian cents from 94.15 cents to be little changed from its level in Asian at the end of last week of 93.97 cents. It dropped to 74.47 yen from 74.96 yen last week.