Video footage has been aired by the Seven Network purportedly showing Bennell in a scuffle at club 189 in Fremantle on Sunday night.
Bennell reportedly failed to show up to training the next morning.
Fremantle released a statement saying they are investigating the alleged incident.
Several years ago, Bennell was rated as one of the AFL’s most promising players.
However, he has endured a string of injury problems amid off-field indiscretions since joining the Dockers from the Gold Coast two years ago.
Fremantle have stuck by Bennell to this point.
But midway through last year, they ordered him to undergo counselling and fined him $10,000 – half of which was suspended – after he displayed bizarre behaviour while watching a WAFL game.
The 24-year-old twice interrupted the three-quarter time huddle of the match between Peel Thunder and Swan Districts to speak to his cousin Traye Bennell.
Bennell was also kicked off a Gold Coast-bound flight before it departed in April because he was intoxicated.
He was banned from driving for nine months after being caught driving while suspended in December 2016.
Bennell’s time at Gold Coast was also plagued by off-field controversies.
Before joining the Dockers, photos emerged of the then-Suns player allegedly using illicit drugs.
However, the Dockers were optimistic Bennell had turned the corner late last season when he made it back onto the park for two AFL games.
Dockers coach Ross Lyon was hopeful of injecting Bennell into the club’s forward and midfield mix for a full season in 2018.
But those hopes could be dashed with Fremantle’s next move set to determine Bennell’s fate.
If the Dockers decide enough is enough and axe Bennell, it’s unlikely another AFL club will pick him up given his troubled history.
But counting in Bennell’s favour is the fact that Fremantle never issued him a public final warning for his previous indiscretions, meaning he may be given another chance to win back the club’s trust.
Bennell’s current three-year deal runs out at the end of 2018.
Last season, Lyon spoke about the need to understand just how hard Bennell’s injury setbacks have been, and how they have played a part in his off-field misdemeanours.
“It would be a terrible shame, wouldn’t it, to lose a young indigenous footballer in this country of this level of talent?” Lyon said.
“If anything, it’s been self-harm that Harley’s been involved with … it’s not great for Harley more than anyone else.
“It’s been a tough road. He is working his way through (the calf injuries) with great character and great resilience.
“I can tell you, I would have crumbled. I would have been out of the system by now. I would have flicked the bails.
“He has great mental toughness. He is a better man than me.”
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