Mr Key distanced the World Cup on home soil from the International Cricket Council's investigation in London, noting that the inquiry was focussing on events that took place in India.
He pointed to New Zealand's reputation for transparency and low levels of corruption both in sport and as a country.
"I'd hate to think that the behaviour of a couple of individuals, if they are proven to be correct, would reflect on New Zealand as a whole. I don't think that would be fair.
"I expect most international people would look at our cricketers and at our other sportspeople and say that they're good, honest people and they try their very best.
"They don't do anything to gerrymander the result of the game."
He echoed cricketing legend Martin Crowe's hope that the ICC investigation would be completed before the event began, but added that this was unlikely.
"It's a very complex issue, it'll have to go through a process of proper justice.
"Whether that can be resolved by the time Cricket World Cup is hosted in early 2015, I'd be somewhat surprised."
Mr Crowe and another test captain Glenn Turner have said the ICC needed to act quickly and resolve down the problem as soon as possible.
Asked how New Zealand would respond to the threat of illegal betting syndicates during the event, Mr Key said New Zealand bookmaking was already outlawed in New Zealand and people had to make bets through the TAB.
Legislation was being introduced which would criminalise match-fixing, and it was expected to be passed into law before the World Cup began in early 2015.
Government was unlikely to establish a new ministerial portfolio for the event, as it did during for the Rugby World Cup in 2011.
The cricket competition was less complicated than New Zealand's hosting of the Rugby World Cup because most of the infrastructure was already in place.
Match-fixing investigation timeline
Dec 5: Trio of cricketers under investigation revealed
Dec 5: 'My heart sank' - Cairns
Dec 6: Cairns' legal team strikes back
Dec 8: Fixing won't die off - Modi
Dec 9: Cairns: I'm still in the dark
Dec 14: ICC probes Aces match in South Africa
Feb 9: Cairns hits back
Feb 10: 'Who's putting this in the media?' - Cairns
Feb 16: Experts say loss of income sparks Cairns counter
Feb 27: Vincent admits approach by bookmaker
Mar 27: Cairns' lawyer arrested
May 15: NZC confirm investigation into Auckland games
May 16: McCullum said no to fixer
May 16: Vincent offered cash and a woman to fix
May 17: O'Brien unsurprised at Vincent revelations
May 18: Friends fear for Vincent
May 20: Cairns is player named as Player X
May 20: Cairns denies Player X allegations
