Australia and Reds star Karmichael Hunt was arrested and charged with drug possession in Queensland on Saturday.
Hunt, 31, was arrested and released by Queensland Police, Rugby Australia confirmed in a statement.
"Rugby Australia has today been made aware of an incident involving Wallabies and Queensland Reds back Karmichael Hunt in Brisbane overnight," the statement read.
"It is understood Hunt was arrested and has subsequently been released by Queensland Police.
"Rugby Australia takes all matters relating to the off-field behaviour of its players seriously and has commenced an investigation into the incident in conjunction with the Queensland Rugby Union.
"No further comment will be made at this time."
Hunt's lawyer, Adam Magill, confirmed the six-time Wallaby had been charged.
"An incident involving Karmichael Hunt occurred which resulted in his arrest," he told The Courier-Mail.
"At this stage no further instructions have been taken.
"There were two males involved and there has been a subsequent charge of possession. They have been charged conjointly."