He said data Fonterra initially provided about the presence of a bacteria that can cause botulism had proved incorrect, leading to contradictory advice and confusion amid product recalls from China to Saudi Arabia.

“It’s certainly pretty frustrating, that’s probably the most generous term I could use,” Joyce told Radio New Zealand. “I’d have expected this information to have been available fairly quickly.”

He said about 90 per cent of the contaminated product had been found and Ministry of Primary Industry (MPI) officials hoped to use Fonterra’s product tracking records to locate the rest by Wednesday afternoon.

He said Fonterra had not raised any objection to government officials effectively sidelining the company from the crisis management response.

“Frankly, Fonterra has welcomed it because it will speed up the MPI checking,” he said.

“It’s important that MPI, as the regulator, has to have the confidence, because the rest of the world’s regulators are relying on MPI.”

New Zealand Trade Minister Tim Groser said there was a risk that China, a major importer of New Zealand dairy ingredients including powder used in infant formula, may block more products.

“So far, [there has been] very limited action. But this is likely to change, and it would change in the direction of wider, not narrower,” Groser told reporters.

Fonterra is the world’s largest dairy co-operative and New Zealand’s biggest company, accounting for 89 per cent of the country’s milk production – 15.4 billion litres – in 2011 and recording turnover of US$15.7 billion last year.

Prime Minister John Key, who has been one of the company’s strongest critics since the scare erupted on Saturday, said he could not understand why Fonterra did not act as soon as it knew there was a problem with some of its whey products.

“If in doubt, be immensely careful – park it up somewhere and work out what’s gone wrong and if there’s a real issue here,” he told TV3. “I can’t tell you why that didn’t happen.”

Key has promised a “forensic” investigation onto Fonterra’s handling of the crisis but said the immediate priority was finding the contaminated product to ensure there was no risk to any infants.

Finance Minister Bill English acknowledged New Zealand’s “100 per cent pure”  image had taken a hit but said it was too early to put a dollar figure on the damage.

"No-one can really put a number on any long-term reputational effect,” he  said. “What we know is that if it’s managed well over the next week or so that  will have quite a lot less impact than if it’s managed badly.”

The scare has seen restrictions put on Fonterra products imported into China while Dumex and Karicare, both subsidiaries of French food giant Danone, issued recalls in mainland China, Hong Kong, Malaysia, Singapore, Thailand and New Zealand.

Authorities in Russia also ordered a recall of Fonterra’s products and advised consumers against using them, domestic reports said, while New Zealand and Vietnam both warned parents to avoid some types of Karicare formula.