The Queensland and Australian representative was pulled over on Saturday however has not yet been charged.
The Australian Federal Police refused to confirm details of the investigation however charges could be forthcoming in coming days.
The club has not yet decided on any punishment and said they had informed the NRL integrity unit.
"The Canberra Raiders have been made aware of a drink driving incident involving Josh Papalii which occurred overnight," the club said in a statement.
"Canberra Raiders CEO Don Furner said the club was disappointed to hear about the incident.
"The Raiders will wait for the outcome of the AFP's investigation into the incident before making any further comment."
