Amid concerns about a nationwide baby formula shortage, Sydney parents Adrien Cheng, Reginald Dong and Sarah Kong in separate incidents in the past month had their online orders for tins of baby formula cancelled. They believe it was because of their Asian surnames.

Frustrated by Woolworths' lack of explanation, they have banded together to lodge a complaint to the Australian Human Rights Commission. They are seeking a formal apology.

"They're disturbed and wanting an investigation," said their lawyer Kingsley Liu of The People's Solicitors, working pro bono. "We're preparing the paperwork. If it's not resolved, it will continue to the Federal Court level."

Australian parents have become increasingly concerned about a baby formula shortage of preferred brands, such as A2 Platinum and Bellamy's Organic, calling for Woolworths and Coles to enforce purchase limits and clamp down on bulk buying.

The shortage has been partly fuelled by opportunists bulk-buying formula and shipping it to China where tins can fetch quadruple the price.

Korean-Australian mother Sarah Kong said her account was suspended after she ordered four tins of formula on New Year's Eve and received a confirmation email and the expected time of arrival.

She was told her account was deemed "suspicious" and given no further explanation. She suspects she was blocked because of her Asian surname.

"At every point in this process you have failed in customer service. At worst it is fraud to have accepted the order, taken the money, imply that I contacted you for a refund and then block my account," she said in a complaint to Woolworths.

A Woolworths spokesman said the chain was trying to manage its supplies of formula for its online customers in a period of high demand.

"In some cases we suspend accounts pending a confirmation that the order fits within our terms and conditions. In any case where a customer has had a poor experience, Woolworths apologises for this," he said.

"Customers should contact us directly so we can attempt to resolve the issue."

Following consumer pressure late last year, Woolworths lowered its baby formula purchase limit to four per transaction, while Coles lowered it to two.

Fairfax Media has previously quoted a Woolworths employee who had discovered one delivery address was linked with 20 online accounts. He said the online store was a vulnerability.

"Going back through the order history, I was able to see that almost every single order had been for large amounts of baby formula or milk powder," he said.

"There aren't any real measures in place to stop people buying truckloads of it online and reselling it. It's up to the store to mark the order as 'out of stock' or cancel it if they notice a suspicious purchase but this rarely happens."

None of the three parents has reached a resolution with the retailer or received an individual apology.

Father of a newborn baby boy, Adrian Cheng said he was outraged when Woolworths blocked his account after he ordered four tins of formula. He also suspects Woolworths made its decision based on his surname.

"I emailed them back asking 'why did you ban me?'" he told News Corp. "They called me the next day and said 'potentially you might have had multiple accounts ... We believe you may have committed fraud'. I just feel insulted."

 On Facebook a few days later, he said: "Not even the courtesy of a phone call to validate the order, just an email cancellation and customer service telling me to write an email so they can 'validate' my claims."

Reginald Dong, father to a 16-month-old, also tried to buy four tins but his order was cancelled. He was told that he had breached Woolworths' terms and conditions. He was given no other reason.

Erin Chew, spokeswoman for the Asian Australian Alliance, said following the widespread media coverage of the baby formula shortfall late last year, a "xenophobic spotlight" had unfairly focused on the Chinese.

"We need a change in how Australians view those of Chinese ancestry. The really unfair aspect is that families like Cheng and Dong are well integrated Chinese Australian families," she said.

"Kong being Korean Australian is also clumped into this group just because Kong probably sounds Chinese. How can this not be seen as racial profiling in this country?"

She said the fact there were three similar examples of accounts being blocked showed they could rule out a glitch in the system.

"We think there's potentially more people affected. So we also want to call out for those who have an Asian surname and who have been affected to contact us."

Chinese demand for Western baby formula rocketed after a string of food scares, including the 2008 melamine contamination that killed six babies and made 300,000 seriously ill.