The NRL has been rocked by its first scandal of the off-season, with representative star Valentine Holmes posting a photo to social media overnight appearing to be biting down on a bag of alleged white powder.

The image, which was posted to an Instagram story, has since been deleted, however, not before it was captured and circulated on social media by other users.

It's unclear at the time of publication whether any prohibited substance was in the bag, with the image appearing to be taken in a public place while the player in question held a can of drink.

News Corp are reporting that the NRL have been made aware of the image which circulated on Saturday evening and will launch an investigation, however, at this stage, neither the game's governing body nor the club have made comment.

Zero Tackle have reached out to the NRL and the Cowboys for comment, with the Cowboys posting a brief statement on Sunday morning acknowledging they are aware of the alleged incident.

"The North Queensland Cowboys are aware of a photo posted to social media by a Cowboys player this morning," the Cowboys wrote.

"The club is conducting an investigation as well as assisting the NRL Integrity Unit.

"The Cowboys will make no further comment until the investigations are completed."

It's not the first time an NRL off-season has been hit by incidents involving white powder or illicit substances.

The Melbourne Storm were caught up in an end-of-season incident after the 2021 finals series which led to multiple players being fined and suspended, while in the same off-season Reece Walsh was arrested over drug possession.