Anti-doping officials have met with six top-flight Australian rugby league clubs over the use of banned performance-enhancing drugs.
The Australian Sports Anti-Doping Agency (ASADA) spoke to Manly, Cronulla, Newcastle, Penrith, North Queensland and Canberra.
The six clubs revealed they were under scrutiny following a report into the use of drugs published last week.
The year-long investigation also implicated two Australian Rules teams.
"Sports would be foolish to think that they didn't need to take the integrity of their sport seriously," said sports minister Kate Lundy.
"Australia loves sport and hates cheats, and these allegations offend a strong, ingrained sense of fair play. Australians like winning for sure, but not at all costs. In Aussie Rules, one of the country's most popular sporting codes, players with disciplinary infringements are not even considered for the game's highest honour, the Brownlow Medal. And that's the way fans like it."
"The substance of the issue here is that we do have a fight on our hands. It's a serious one.
"Australians take their sport extremely seriously and as sport minister I will not stand by to allow this kind of thing to go on in Australian sport unchecked."
The Australian Crime Commission (ACC) report
said it had found "widespread" use of banned performance-enhancing drugs
among professional and amateur athletes which also had links to gambling and organised crime.
In light of the findings, all Australian athletes and officials will be forced to sign a legal document regarding their anti-doping history before they can be eligible for next year's Winter Games in Sochi.
Athletes, coaches and officials must declare in the legal document that they have no history of doping, or that they have committed a doping violation and served a sanction.
Anyone who cannot answer yes to either options will be ineligible for selection in the Australia team.
Under Australian law, anyone who wilfully makes a false statutory declaration could face up to five years in prison.
The report said scientists, coaches and support staff were all involved in the provision of drugs across multiple sporting codes, without naming any individuals.
The Melbourne-based Essendon Bombers, one of the country's oldest and most popular Australian Rules clubs, are one of those clubs implicated.
Governing body, the Australian Football League, declined to name the second Australian Rules club in the probe but has confirmed one of its players is under suspicion.
National Rugby League chief executive David Smith said his administration had been working with ASADA for a "number of weeks".
"I can't comment on the outcome on the information we have so far. What I can say is that they're serious matters," he said.
"I have said right from the outset that it involved multiple clubs and multiple players and as a sport we have taken this very seriously in the way we have approached this."