Two Australian Rules football clubs and a number of rugby league teams are being probed for the use of banned performance-enhancing drugs, officials said on Sunday.
Federal justice minister Jason Clare, criticised for releasing a damning report into doping in Australian sports last week that lacked details, confirmed that a number of clubs in the competing football codes were under suspicion.
Clare said authorities had passed on the names of the clubs to both of the sport's governing bodies.
"We've given the names of the clubs to both the NRL (National Rugby League) and the AFL (Australian Football League)," he told state broadcaster ABC.
"And the NRL and the AFL have asked for permission to tell the clubs that are affected by the investigation."
"The (Australian) Crime Commission agrees and we're taking action to allow both the NRL and the AFL to tell the clubs that are involved in this investigation," he added, referring to Australia's top criminal intelligence unit.
"And then it will be up to the clubs to put their hand up and say 'yes, we are one of the clubs that are affected by this investigation'."
One of the AFL clubs, the Melbourne-based Essendon Bombers revealed last week it was under investigation over the use of supplements given to players by team staff, and a senior AFL official said on Sunday that a second team was under suspicion.
"The AFL is aware of potential multiple breaches at (Essendon)," AFL deputy chief executive Gillon McLachlan told reporters.
"The AFL is aware of one case involving the possibility of WADA (World Ant-Doping Agency) prohibited performance-enhancing drug use by one player at one club."
McLachlan declined to name the second club, but added that the cases at Essendon may have involved the players being doped "without their knowledge or consent".
The NRL confirmed that multiple clubs were under suspicion, but would not inform them for "24-48 hours" for legal reasons.
"Once this information is passed on the NRL will not, under the guidelines outlined by the ACC, be able to identify the clubs publicly," the NRL said in a statement.