Australian Rules football has admitted involvement in a nationwide sports doping scandal, saying two clubs and a number of individual players had been implicated.
An Australian Crime Commission report released Thursday said use of prohibited substances including peptides, hormones and illicit drugs was common across multiple sporting codes, sending shockwaves through Australia.
Australian Football League (AFL) deputy CEO Gill McLachlan revealed Sunday that the ACC report had identified "two specific cases where WADA (World Anti-Doping Agency) prohibited performance-enhancing drugs may have been used".
He said the AFL was aware of "potential multiple breaches" at Melbourne's Essendon Bombers, where "it is possible that players were administered the WADA-prohibited performance-enhancing drugs without their knowledge or consent".
One player at another club had also been identified, he added, declining to identify the individual or their franchise.
"All possible instances of WADA-prohibited performance-enhancing drug use identified will be investigated fully in co-operation with ASADA (Australian Sports Anti-Doping Authority) to determine whether in fact there have been any breaches of the AFL's anti-doping code," McLachlan told reporters.
However, he said the AFL was not aware of "any instance of suspected match fixing in the AFL competition".
Separately, News Limited reported that six of Australia's 16 National Rugby League sides had been named in the probe, citing confidential sources.
NRL chief Dave Smith would not confirm the report but said the sport was working closely with the ACC to "inform individual clubs that they have been the subject of intelligence-gathering".
"While acknowledging media speculation about the number of clubs today the NRL remains bound by strict legal constraints," said Smith.
"The NRL accepts that there are frustrations for players, clubs and fans. However, the significance of these matters demands they are dealt with through a proper process."
Justice Minister Jason Clare stressed it was up to individual clubs to come clean on their involvement and not the place of the government or ACC -- a stance backed by Smith.
"It'll 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," Clare told ABC television.
Clare said the "veil of suspicion is hanging over all clubs" and "silence is not going to be the solution here".
"I encourage all clubs that are affected to put their hand up and work with the authorities to make sure that we get this out of the game," the minister said.
Prime Minister Julia Gillard -- a renowned AFL fan -- echoed the calls, urging transparency to restore trust in the sports-mad nation.
"I think fans are anxious to get to the bottom of this and fans are very anxious to know what the circumstances of their own club are," said Gillard.
"So I would say to clubs, please come clean; make sure that you tell your fans what is going on."
High-profile doping cases have been rare in Australia, with bans for cricketer Shane Warne in 2003 and rugby's Wendell Sailor in 2006 among the exceptions.
Cycling Australia officials Stephen Hodge and Matt White departed the body in October in the wake of the scandal involving disgraced US cycling star Lance Armstrong, when they admitted taking drugs during their riding careers.