Officials had been in touch with Chinese agencies since Fonterra told the Government of the problem, he said tonight.
Fonterra today admitted it had known of the contamination since August, and said it had urged Chinese executives to mount a public recall.
But until today it did not disclose publicly information about the poisoned milkpowder, which is reported to have killed one baby and made another 432 sick with kidney damage.
Mr Goff said tonight he did not believe the scandal would damage New Zealand's trade interests in China.
"I don't think this is something that is caused by Fonterra, or directly under the control of Fonterra," he told NZPA.
"I have had the assurance from Fonterra that they did everything within their power to ensure the product was recalled and that the local authorities in the city ... where they are operating were fully informed of that problem."
Other major dairy companies, such as Nestle, had been caught up in similar scandals in the past and it was possible several other companies had also supplied the contaminated milkpowder.
Fonterra said today it had pushed for a full public recall of all affected product since learning of the problem last month.
"From the day that we were advised of the product contamination issue in August, Fonterra called for a full public recall of all affected product," the company said in a statement.
" Consumer safety has always been our number one priority."
Fonterra has a 43 percent stake in Shijiazhuang Sanlu Group Co Ltd, which ordered a product recall on September 11.
The Chinese Government has since ordered it to stop production.
Many babies have suffered kidney stones and other damage from milkpowder adulturated with melamine, a chemical which can boost the apparent protein content in some standard tests on foods.
The Fonterra spokesman said company representatives in China were seeking a meeting with the Chinese government to discuss the issue.
"We will be assisting where we can with the investigation," he said.
But because an investigation was under way, "and the sensitivities around it", the company declined further comment.
Vice Governor Yang Chongyong of Hebei province, where Sanlu Group is located, said investigators wanted to know whether information on the contamination was suppressed.
"We will look into whether government at any level was negligent or whether any officials tried to withhold information," Yang said.
"If we find anyone did this, they will be held accountable."
China's health minister has blamed the Fonterra joint venture for delays in warning the public about the contaminated milkpowder, the Associated Press news agency reported.
Government officials said 19 people had been detained and 78 were being questioned about how the banned chemical melamine was added to milk sold to Sanlu Group China's biggest milk powder producer.
Officials complained they were not alerted until September 9, even though Sanlu got complaints as early as March and its tests found melamine in the milk in August.
"The Sanlu Group shoulder major responsibility for this," Health Minister Gao Qiang said.
He gave no indication of what penalties the Chinese dairy might face but said those responsible would "be dealt with severely".
Fonterra's business in Taiwan imported the contaminated milkpowder, some of which had been sold to be used in food manufacture.
Liu Fang-ming, of Taiwan's Taoyuan County Government, said a 25-tonne shipment arrived in June but that less than 10 tonnes had been recovered.
