Sydney Swans CEO Tom Harley and coach John Longmire have denied knowledge of alleged widespread cocaine abuse in the AFL.

Evidence of the allegations has surfaced from former club officials and a player's father.

The AFL acknowledges illicit drug testing but refutes claims of a drug problem within the league.

A 'three-strikes' policy is part of the AFL's current illicit drugs protocol, which is under review.

Critics argue the AFL's policy on drug use lacks transparency and fairness, with few players actually stood down.

The AFL faces a dual challenge of managing drug use to avoid positive game day tests while caring for player welfare.

Pressure is mounting for the AFL to address the 'bad culture' of drug use and ensure policies benefit athlete health long-term.