Canberra, May 4 (IANS): Australians affected by COVID-19 travel restrictions have been encouraged to take legal action against airlines which exchanged tickets on disrupted flights for vouchers.

On Monday, law firm Slater and Gordon said they believed that leading Australian airlines, including flag carrier Qantas and Jetstar, may have been unlawful in offering vouchers rather than cash exchanges, reports Xinhua news agency.

The firm reported being in contact with Australians who said they were thousands of dollars out of pocket after receiving vouchers which could be used for future flights that they may never be able to redeem.

"We understand that everyone is doing it tough at present, including the major airlines and travel companies, but that doesn't give them an excuse to take advantage of their customers," Practice Group Leader Andrew Paull said.

"We believe cash refunds should be returned to customers, who almost certainly need that money right now ... If they won't do so, then it's only reasonable for those customers to look at recovering their money through a class action."

The firm also questioned the airlines continuing to offer tickets on international flights as early as June 1, despite warnings from the government that travel bans could stay in place for much longer.

As of Monday, there were 6,823 COVID-19 cases in Australia, with 96 deaths.