Australian supermarket giant Coles says panicked shoppers have bought up to three Christmases worth of stock in as many weeks amid the coronavirus pandemic.
Coles chief operations officer Matthew Swindells on Friday compared the scale of hoarding to festive seasons - but without the usual six months of lead-up planning.
"It's not a problem of supply, it's a problem of demand," Mr Swindells told the Seven Network.
"We have done three Christmases in three consecutive weeks from a standing start.
"When you see that immediate lift in demand across a network as large as Coles, it punches a huge stock hole in our supply lines and it takes time to recover."
Australia produces enough food for 75 million people, or three times its population, but shelves have been stripped bare as shoppers fear being locked down because of COVID-19.
NSW Premier Gladys Berejiklian followed Queensland's lead on Friday by announcing the lifting of curfews to allow supermarket deliveries around the clock.
Road Freight NSW says the initiative will help reduce loading and unloading times for truck operators due to "massive choke points" across the network.
"What used to take 35-50 minutes (and 90 minutes for a B-double) at a distribution centre to load a truck for a supermarket delivery, is now taking up to five-six hours," the peak body's chief executive Simon O'Hara said in a statement.
"Given that most supermarket bays can handle one or at most two trucks at a time, it's causing lengthy build-ups for deliveries.
"Truckies are telling us they're being delayed for days or even up to a week."
Mr Swindells said Coles had been working closely with governments to keep the supply chain open.
"There is no need to panic," he said.
"Don't stockpile and give us the time to turn the dials we have turned and get all the stock back onto the shelves.
"But it will take time and it will need cooperation between the Australian public and the retailers."
Yet Prime Minister Scott Morrison's plea for Australians to stop hoarding appears to have been lost on anxious shoppers.
People were queuing out the door at Woolworths' Marrickville Metro store on Friday morning.
"I had to wait 20 minutes, the line was probably 40 people deep," Sydney woman Jane Zouch told AAP.
"Everyone ran straight for the loo paper and pasta aisle."
The lack of supplies in cities across the nation has forced regional supermarkets to take extraordinary steps to keep essential items available for locals.
To counter busloads of "shopping tourists" cleaning out shelves, IGA Broadford - about 70 kilometres north of Melbourne - is checking identification and refusing entry to non-locals.
"Due to the current situation, we can only accommodate customers living in these areas," read a notice posted on the store's window.