England Cricket have reportedly opened an investigation into claims that wicketkeeper-batsman Jonny Bairstow headbutted Australian opener Cameron Bancroft at a bar in Perth earlier this month.
The incident is alleged to have taken place while England were in Bancroft's home town of Perth for their opening tour game.
It is unclear what provoked the alleged incident with Bancroft said to have not retaliated.
Coach Trevor Bayliss had earlier said that there would be no ban on alcohol on the tour but asked the players to exercise restraint and discretion.
Bayliss said: "The players sat down and had a chat.
"They are the ones who have come up with this.
"There are no set curfews, they are just sensible rulings.
"To me, it's what we should have been sticking to anyway as players or people around a professional set-up.
"Not drinking between matches is just sensible. We certainly don't want to keep players in their rooms because it is a long tour. You have to get out and experience what the country you're touring has to offer.
"It's about picking the right time to have a couple of drinks, but knowing to stay away from it if you're preparing for a match."
The ECB have yet to comment on the incident with Australian news outlets breaking the news.