Hunter Paisami and Pone Faamausili had admitted their involvement in a late-night incident in Melbourne, with Faamausili providing a statement to police on Sunday, a report on Rugby Australia's website said.
The allegations come a week after Rebels number eight Amanaki Mafi faced a court in Dunedin, New Zealand, after being charged for his part in a violent clash with team mate and Wallabies loose forward Lopeti Timani.
Prop Faamausili made his Rebels debut earlier this season and recently re-signed until the end of the 2020 season.
Centre Paisami, 20, has yet to make his senior debut.
The Rebels had launched an internal probe into the incident and alerted the sport's national governing body Rugby Australia, a spokesman said.
The incident was brought to light by a social media post from a relative of the alleged victim, the Rugby Australia report said.
The allegations have added another sour note to a disappointing season for the Rebels, who narrowly missed out on the playoffs after being eliminated in the final round of the regular season.
(Reporting by Ian Ransom; Editing by Greg Stutchbury)
