The AFL has confirmed it is looking into allegations Clarkson used "profane language" following an umpiring decision during last Saturday's 59-point loss to Port Adelaide.
The league is trying to work out exactly what Clarkson said and whether the allegedly abusive language was directed at officials.
The incident could trigger a suspended two-match ban that hangs over Clarkson for the homophobic slur he directed at St Kilda players during a practice game in March.
"The league are looking into an incident on Saturday where North Melbourne coach Clarkson, coaching from the bench, used profane language that was audible to others (including match officials) following an umpire's decision," AFL spokesperson Jay Allen said in a statement on Wednesday night.
"An update will be provided once enquiries are completed."
North Melbourne have been contacted by AAP but declined to comment while the AFL investigation is ongoing.
It comes less than three months after Clarkson was found guilty of "conduct unbecoming" over his expletive-laden tirade against St Kilda's Jimmy Webster and Dougal Howard during a practice match.
The 55-year-old used the homophobic slur "c*******er" during that exchange with the Saints players and was hit with a $20,000 fine, as well as a two-match ban, which was suspended until the end of the 2025 season.
If found guilty of "conduct unbecoming" again, Clarkson would trigger the two-match ban and face additional sanctions for the further breach.
Following the incident in March, Clarkson apologised to the St Kilda players and vowed to work to control his temper.
"I am disappointed that I allowed the emotion of the moment to envelop me and I should not have engaged with the St Kilda players," Clarkson said at the time.
"I have since apologised to St Kilda coach Ross Lyon, Jimmy Webster and Dougal Howard for the manner in which I reacted.
"This has been a significant reflective moment for me.
"My language was not used with any intent to vilify or marginalise, however through this incident I have begun to understand the impact of the use of casual language.
"I am fully committed to educating myself in this regard."
Former Hawthorn coach Clarkson has a long history of flare-ups and confrontations, which includes 12 misdemeanours since 2006.
