Lessons need to be learned about the damage of false allegations, according to Countdown boss Dave Chambers.
The Commerce Commission has cleared the Countdown supermarket chain of allegations of anti-competitive behaviour, made by then Labour MP Shane Jones in the last Parliament.
Mr Chambers, the managing director of Countdown owner Progressive Enterprises, told Checkpoint he still had no idea where the accusations of blackmail and extortion came from but that lessons needed to be learned about the damage false accusations could do.
"It was sparked by some pretty outrageous allegations made under parliamentary privilege," he said.
"Extremely hard words and criminal behaviour, of course, one of them, so very pleased that there's no evidence. That's what I said at the time, and we're pleased that that's been borne out in the report."
The investigation found no evidence that Countdown broke the law.
Commission chief executive Brent Alderton said almost 90 complaints were received, but the inquiry had cleared the Australian-owned chain of co-ercing or misleading its suppliers.
"The supermarket industry is highly concentrated and it is important to the New Zealand economy, it touches the lives of all New Zealanders.
"This means that the detriment wound be high if a breach was found."
Mr Alderton said the investigation did, however, show ambiguity in business communications and warned that discussing competitors' prices with suppliers put companies at risk of prosecution.
The investigation began in February this year after Shane Jones told Parliament that Countdown had forced suppliers to pay it retrospective payments for losses it suffered in 2013.
Food and Grocery Council head Katherine Rich said she stood by her earlier claims based on information received from members.
"It's important to emphasise that while the commission has concluded there were no technical breaches of any law, that doesn't mean business behaviour that New Zealanders would deem unfair has not occurred," she said.
"The fact that there were 90 official complaints to the commission speaks volumes."
It was time to consider whether a legislated grocery code of conduct was needed, Ms Rich said.
Previous Commerce Minister Craig Foss had hinted the Government could impose a compulsory code of conduct on supermarkets.
But new Commerce Minister Paul Goldsmith said there was no immediate need for one and that the Commerce Commission investigation was robust.
"The Australians are currently consulting on a prescribed voluntary code of conduct and we'll be very interested to see where that ends up," he said.
"My officials are closely watching that. We'll take a good look at the report from the Commerce Commission and, if we identify any issues that need to be resolved, we'll consider that carefully over the next few months."
However, Labour's commerce spokesperson Clayton Cosgrove said while the commission found no technical breaches of the law, the fact there were 90 complaints indicates there are serious problems and a mandatory code of conduct is needed, overseen by an independent adjudicator.
"We believe there is an issue here, we believe there's an opportunity to resolve that issue and ensure that everybody gets a fair go, and we have a piece of legislation that says we'll have an adjudicator, independent, paid for by the industry, lean and mean, with teeth, mandatory code of conduct," he said.