A leading law firm is investigating a class action over the federal government's $100 million community sports scandal.

Slater and Gordon's class actions practice group leader Andrew Baker says tens of millions of dollars in sporting club grants were awarded to clubs whose applications for funding would otherwise have been unsuccessful.

That's because then sports minister, Deputy Nationals Leader Bridget McKenzie, applied her own decision-making criteria to overrule the merit-based assessments made by Sport Australia

Mr Baker said that the clubs Sport Australia decided were worthy of funding but missed out may have rights to seek legal remedies.

"Every dollar that went to a club whose application should have been unsuccessful is a dollar that didn't end up with a club that Sport Australia had identified and recommended for funding in the course of proper processes," Mr Baker said in a statement on Sunday.

"These community organisations, clubs and groups have lost out because it appears public funds were used for political gain."

He said a thorough investigation by the Australian National Audit Office has stated that there was no legal authority evident to it which allowed the minister to approve the grants, rather than Sport Australia.

"This raises serious questions about the lawfulness of the conduct involved," he said.

"In these circumstances, the clubs that have suffered because of any unlawful conduct may have rights to seek legal remedy."

Mr Baker encouraged clubs who missed out on grants to contact Slater and Gordon.

Senator McKenzie is already under pressure to step down from the government frontbench with Labor, the Greens, One Nation and independent MP Zali Steggall having all backed a senate inquiry into the controversy.