The men were taken into custody at a Rosebery storage facility about 4pm on Wednesday, not far from the Mascot freight depot from which the tests were allegedly taken on Tuesday afternoon.

Two storage units are being searched following the arrests, with charges yet to be laid.

The tests are believed to be worth more than $500,000 and the alleged theft comes amid a nationwide shortage of the kits.

NSW Police were called after a man walked into the freight depot in Mascot on Tuesday afternoon and "took possession" of the tests.

Premier Dominic Perrottet on Wednesday warned the culprit to expect a visit from police.

"At a time when everyone across our state has made incredible efforts in keeping people safe, in making sacrifices, what a disgraceful act," he said.

"The police will catch you."

Australia continues to grapple with a shortage of rapid antigen tests and price gouging which the consumer watchdog has called "beyond outrageous".

Australian Competition and Consumer Commission boss Rod Sims says the agency has received reports of RATs costing up to $500 for two tests through online marketplaces, and more than $70 per test through convenience stores, service stations and independent supermarkets.

Despite wholesale RAT costs being up to $11.45 a test, the agency said prices for the kits are often retailing between $20-$30 and are priced much higher through smaller outlets.

Australian Associated Press