Since China reported the first case of ASF just over a year ago, it has culled more than 131million pigs, or around 40% of the previous pig herd.
NZ Pork was concerned the disease was spreading "quite rapidly" and was now in Timor-Leste, or East Timor, as it continued to move south from China. It has been confirmed in the Philippines and South Korea.
"People need to realise this is a huge risk to an industry in New Zealand," Mr Roy said.
Last week, he met MPI director-general Ray Smith to outline where NZ Pork believed the greatest risks lay.
There was no resistance to the disease and no known vaccines. The focus had to be on keeping the disease out of New Zealand, and intercepting "every single illegal effort" by travellers to bring any meat protein into New Zealand, which he believed was the biggest risk, he said.
If the disease came into New Zealand, it had to somehow get to pigs and Mr Roy believed the biggest risk was swill feeding by "backyard operators". Bona fide pig producers knew the risk and did everything properly, he said.
Clutha-Southland MP and National's associate agriculture spokesman Hamish Walker said biosecurity measures needed put in place to protect New Zealand's pork industry.
"The minister needs to prioritise biosecurity so African swine fever does not arrive in New Zealand. Steps need to be taken at the border to stop it from getting in.
"This includes signage at places of entry to New Zealand, 100% interception of attempted illegal trafficking of pork product, assurance imports are meeting required standards, hunters from foreign countries being given adequate checks on equipment brought into New Zealand and migrant workers returning or entering New Zealand not bringing apparel which could be a source of infection in with them."
The disease was easily spread from sick pigs to healthy pigs and could also be carried on contaminated equipment and in animal feed, Mr Walker said.
Biosecurity New Zealand director animal health and welfare Chris Rodwell said Biosecurity NZ was taking the threat from ASF "extremely seriously".
New Zealand has had import restrictions in place for pork products for many years while additional measures had been taken since the start of the global outbreak last year.
"We are working closely with the industry to enhance awareness of ASF and its signs among veterinarians, farmers, hobby pig owners and hunters.
"We are also communicating the rules/restrictions on feeding uncooked waste meat to pigs. Making sure pigs are not fed uncooked meat waste is a vital part of limiting the spread of ASF (if it ever gets to New Zealand)," Mr Rodwell said.
There were strict rules for feeding meat or food waste containing meat to pigs. For offences under those regulations, individuals could be fined up to $5000 and businesses could be fined up to $15,000.
Biosecurity NZ was also working with the industry to ensure importers understood commercial pork products could be imported into New Zealand only if they met strict conditions that ensured the products were free from ASF.
"Fresh or frozen pork can only be imported from ASF-free countries, zones or regions. All other pork products imported to New Zealand must undergo a heat treatment process, such as canning, which destroys the ASF virus.
"Personal consignments of fresh and cured pork products from any countries are not permitted. It is important to note we do not import live pigs into New Zealand," he said.
Biosecurity NZ was monitoring the situation and would change the import rules for pork products again if it needed to.
Signage was recently introduced at international airports to alert arriving travellers of the risk of bringing pork products into New Zealand, he said.
BNZ's Rural Wrap said Chinese meat import demand had been further boosted over the past year as ASF caused a mass culling of pigs in China.
China's Ministry of Agriculture and Rural Affairs expected a rebound in pig numbers next year, although some in the private sector believed it could take years to rebuild pig stocks.
Pork prices in China had lifted more than 69% over the past 12 months, including a 20% lift in September.
Before the disease, pork made up about 70% of China's total meat consumption, so there was a "massive" hole to fill, senior economist Doug Steel said.
Unsurprisingly, Chinese increased demand for substitute meat had concentrated on typically lower-valued products, including the likes of lamb flaps and mutton.
But with more demand for typically lower value cuts, it was likely that some upward price pressure would filter up to the premium product spectrum for both lamb and beef - at least to some degree.
While the precise diffusion was subject to conjecture, there was little doubt that ASF was having a material effect on meat prices around the world, he said.
