At least two Melbourne-based AFL players have sought treatment for addiction to the drug methamphetamine, according to News Ltd.

A report in Melbourne's Herald Sun claims two drug clinics are known to have treated footballers battling addiction.

The report claims the players went alone in seeking help as they feared the consequences from their club and the AFL.

The claims from News Ltd come just days after Collingwood chief executive Gary Pert said illegal drug use among AFL players was the biggest problem in the game.

Pert is adamant he was talking about AFL footballers in general, not specifically Collingwood players.

The Pies chief has led the push for a January forum involving all 18 clubs on illicit drug use.

On Thursday, the Magpies were forced to defend themselves after a Fairfax report slammed the off-field behaviour of champion midfielder Dane Swan.

"Swan is not the only player at Collingwood who has been a law unto himself during his end-of-season break but he has been a dreadful influence for some time," Fairfax journalist Caroline Wilson wrote.

Under the AFL's three-strikes illicit drugs policy, club officials are kept in the dark until a player registers a third positive test.

A concerned Pert says players are at a high risk during the off-season when they are away from their club and the and the day-to-day regime of training and playing.

"There's volcanic behaviour ... there's definitely a concern that's been raised to all of the club CEOs and the AFL are very aware of this," Pert said.

"By the nature of the disciplines we put in place for the players ... at times, especially during the off-season or when we have breaks, (they) are deemed the highest-risk times.

"Having that sort of knowledge and being aware of it helps the clubs and helps the AFL deal with that."

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