Woolworths has blamed a “terrible IT problem” for days of ongoing supply issues at some of its busiest outlets in Queensland.

Frustrated customers have flooded social media with pictures of empty fruit and vegetable shelves at Woolworths in the state’s south-east in recent days.

The images evoked the worst days of the Covid pandemic, when supermarket shelves across Australia were stripped bare of staples such as pasta, toilet paper and fresh fruit and vegies.

On Monday, Woolies’ chief commercial officer, Paul Harker, blamed a “warehouse management system upgrade” that had gone wrong. The glitch had caused “carnage” for the company’s supply chain, including getting stock to outlets in Brisbane and south-east Queensland, he said.

“We’ve had a terrible IT problem,” Harker told the Queensland government’s supermarket pricing probe.

“We’re not particularly happy about the situation.”

Harker apologised to customers who couldn’t get what they wanted, and said the company was working to resolve the issue.

“I might add we’re continuing to take the committed stock from our suppliers, even if we can’t get it out,” he said.

Contacted on Tuesday, Woolworths said it had no further updates on the issues.

Also on Tuesday, smaller grocers slammed business tactics used by retail giants, telling the Queensland inquiry they have been “annihilated” by major supermarket chains.

The company behind IGA criticised the practice of rezoning land to allow for major supermarkets to establish themselves in an area.

Metcash government relations manager Luke Mackenzie cited an example in which Coles bought an entire shopping centre in the inner-Brisbane suburb of Milton.

He told the inquiry the local IGA was forced to close, and called on the Australian Competition and Consumer Commission to unwind the “ridiculous” acquisition.

“The community is outraged that they are losing the only independent left in that market when Coles is already present twice,” he said.

Roz White, who owns and operates a Sunshine Coast IGA supermarket, said her business was “taken out at the knees” when a major supermarket came to town.

“We were the only supermarket in town and a major competitor came into that catchment and just annihilated us financially,” she said.

Foodworks Queensland operations manager Wayne Mason said smaller retailers being forced to close when a major supermarket moved in “happens all the time”.

“Your choices are either ‘I’m going to play the game, invest more money and probably get burned’ … or ‘do I exit now?’, ” he said.

“What it does to families and what it does to small business is wrong.”

Availability of land was also a challenge for smaller retailers, with Aldi telling the inquiry it had limited its ability to expand regionally.

National buying managing director Jordan Lack said Aldi had to assess cost, population and proximity to distribution centres.

“It’s really important for us to consider not only what we do, also what we don’t do and unfortunately that means we can’t be the same as our competitors,” he said.

“We can’t be in all communities and that is a deliberate decision.”

The German grocer, which represents about 10 per cent of the Queensland market, has also chosen to avoid click and collect shopping and home delivery.

Lack said this had to do with keeping prices low.

Queensland Premier Steven Miles proposed the inquiry to examine the gap between grocery prices and what farmers are paid for produce amid the cost-of-living squeeze.

He made a surprise appearance on Monday to ask Woolworths whether it would apologise to families doing it tough and rebuke Coles for a perceived lack of contrition.

The inquiry will hand down its report at the end of May.

-with AAP