Late on Saturday, the Saints revealed the AFL integrity unit was looking into an incident involving their players during Friday's VFL game against Frankston.
It later emerged that the player is Collard, who was banned in 2024 for slurs in the VFL.
Collard will also face scrutiny for high contact on a Frankston player, sparking an on-field brawl.
"St Kilda is aware of an alleged incident involving one of its players during last night's VFL match against Frankston," the club said on Saturday.
"The club takes matters of this nature extremely seriously and is working closely with the AFL integrity unit as it conducts its investigation into the matter.
"While this process is underway, it would be inappropriate for the club to comment further."
Collard's 2024 ban while he was playing for VFL side Sandringham, then affiliated with the Saints, was among several cases of homophobic slurs that prompted an AFL crackdown.
It culminated in Adelaide star Izak Rankine being banned for four AFL games at the end of last season after an incident in a game against Collingwood.
Rankine missed the Crows' finals series and returned from the suspension for their round-three loss to the Western Bulldogs.
Collard has played 15 AFL games for the Saints since his 2024 debut.
As well as the ban two years ago, he also took part in a Pride in Sport education program
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