The decision not to go public earlier was based on police advice and the fact that the threat letters indicated no contamination was planned until after the March 30 deadline the author of the letters had set for the government to ban further use of the 1080 pesticide.
Taiwanese media had said it would have been better to go public immediately so consumers don't lose trust in New Zealand's food safety.
Chung said they compared it to how quickly information was provided last year when dairy cooperative Fonterra recalled a batch of fresh cream supplied to Anchor and Pams due to the risk of E coli contamination, and referred also to communication problems in 2013 during the botulism scare, which later turned out to be false.
"Food safety is the number one issue in Taiwan and China and they feel New Zealand is one of the last places which has high quality, clean and safe dairy products.
"Chinese consumers trust the New Zealand brand but also say the country shouldn't take that for granted because they do have other choices in the market now. Germany and Japan are also well-regarded in terms of dairy products."
Expatriate business adviser David Mahon, who has been based in China for decades, said yesterday the eco terrorist threat was unlikely to gain traction because there had been no actual contamination of any product.
There have been concerns over how social media in China will react, given criticism of Fonterra's handling of the botulism scare.
Mahon said the Chinese government, which has a lot of control even over social media, continued to have confidence in New Zealand's dairy supply chain.
Every fresh batch of infant formula was now being tested for 1080, with none found in any product so far. Supermarkets are also taking extra security measures over infant formula products in store.
Foodstuffs said today it had implemented a number of additional security protocols through its supply chain, including subjecting customers to heightened surveillance when entering a Foodstuffs store and appointing an infant formula milk monitor in larger stores, who will visually monitor the product on the shelf and give customers the Ministry of Primary Industries consumer guide on how to check for tampering.
The food retailer said feedback from customers on the security measures implemented yesterday had been positive, with customers saying that felt reassured there was a physical presence watching over the product.