Partners in the law firm Clinch Neville Long Letherbarrow said their planned lawsuit includes a number of employees who allege the federal Australian Quarantine and Inspection Service was, in part, responsible for the outbreak, The Sydney Morning Herald reported Saturday.

"They include vets, saddlers, riding schools, instructors, farriers, equestrian associations, suppliers and breeders," law firm partner Matthew Hourn said of the plaintiffs in the civil suit.

"Tens of thousands of people lost their income."

Hourn also warned that if retired High Court judge Ian Callinan's inquiry into the outbreak at the Eastern Creek quarantine station is delayed, the suit would be filed immediately.

"The damages are astronomical," Hourn said. "It's likely to add up to hundreds of millions of dollars in compensation."

To date, 46,000 horses have become infected with equine influenza during the outbreak, the Herald reported.