A Woolworths spokeswoman said a two-pack purchase limit had been introduced in NSW, the ACT and Victoria to manage stock delays.

“Along with other retailers, we’re expecting a short-term delay in stock from one of our egg suppliers in NSW, ACT and Victoria, due to the temporary closure of one of their packing sheds,” the spokeswoman said.

“Their supply is expected to recover over the next week as they ramp up operations at their other sites.”

Coles introduced a similar policy earlier in June.

The limit comes after bird flu was detected at an eighth Victorian farm on Tuesday, and as ACT authorities investigate a suspected outbreak on a commercial egg farm in Canberra.

There are two known outbreaks in NSW, with authorities there working with those in the ACT, NSW Agriculture Minister Tara Moriarty said in a statement.

“The ACT commercial egg farm has been locked down with no products, eggs, and machinery allowed in or out, and the site’s hens will need to be depopulated,” Ms Moriarty said.

So far more than one million chickens have been destroyed nationally to limit the spread of the disease.

Ms Moriarty said avian influenza was not a food safety concern and it was safe to eat poultry meat and eggs after proper handling and cooking.

Victoria’s Agriculture Minister Ros Spence on Thursday launched two mobile command centres to help manage the state’s outbreaks.

“Biosecurity emergencies can happen in any corner of our state and these new mobile incident command centres are key to ensuring we can get our expertise on ground as quickly and efficiently as possible,” Ms Spence said.