Jason McGrath, cousin of Lions' premiership player Ash McGrath, was reported to have told the Courier-Mail that six players were heavy users of speed, ecstasy and marijuana between 2002 and 2009.
The article also said McGrath claimed to have been involved in fixing a Lions match in 2003.
McGrath, a self-confessed drug dealer, allegedly said members of the coaching staff knew some players were regular users of illicit drugs, and claimed he had once delivered an ounce of speed to a players' Mad Monday celebration at the Broadway Hotel.
The Lions have hit back, saying the story was published without any evidence.
"These claims from a "self-confessed drug dealer" are completely unsubstantiated and do not deserve publicity," the club said in a statement on Monday.
"We have no reason to believe the word of a "self-confessed drug dealer" but if anyone, including the Courier-Mail, has any evidence with regards to this, or any other matter, it should be referred to either the AFL integrity unit or the Queensland Police."
Among other claims, McGrath alleged he had supplied cocaine to players.
The Courier-Mail reported that it contacted Jason McGrath after he suggested on Facebook he could expose illegal practices.
"If you don't think the drugs and match-fixing is real, I bet on the AFL and was involved in a game being fixed," he said on the social media website.
On Monday morning, triple premiership Brisbane Lion and Brownlow medallist Jason Akermanis said he couldn't remember Jason McGrath, who reportedly had been seen in the club's change rooms and at functions during that period.
He said he found it hard to believe spot fixing had occurred despite McGrath's claim he would provide the Courier-Mail with betting slips and phone records to back his allegations.
"I find things like this extraordinary. If it's only a couple of players and he's got a vendetta against a couple, why would he be admitting it to the world and also implicating himself?" Akermanis told SEN.
"If he can prove it, I'd love to see it.
"The older players would have generally been playing every game … I've got no doubt none of them were involved at all.
"If they were, that would really surprise me."
Akermanis said if there was proof that players had been tainted by drug use, they deserved to be exposed.
"It's a long time ago, I must admit that. Things that happened on Mad Monday… I wouldn't have seen anything because I couldn't remember, because I was too drunk," he said.
"The rest of it, I don't know. If it sorts out a couple of things and/or finds some fault, then very good. Everyone should be accountable.
"I'm not saying we should dismiss it. If you've got proof, show the proof.
"If he's happy to bring everyone down, including himself, go nuts and if that means the game is better for it, then I could not care less.
"We won a lot of games and had a fantastic career, but if there were a couple of shady blokes in the team that would never surprise me, because there are a lot of them."
The Courier-Mail said four players named by McGrath were still playing in the AFL.
The AFL declined to say if it would investigate the claims.
McGrath reportedly has since refused to return the newspaper's phone calls and claimed to have received threats from a current player after the Facebook claims.
