The serving of full-strength beer and the use of capsicum spray to subdue fans will be subject to review when the tournament ends.

Three members of the Hellas Fan Club were banned from the Open yesterday after a brawl at Margaret Court Arena on Tuesday night where capsicum spray was used on members of the crowd.

All three are facing charges of assaulting police and resisting arrest, while police will question a further seven men in the coming days.

Greek tennis supporters are considering legal action against police who have been accused of heavy-handed tactics.

An investigation has also been launched into allegations a 12-year-old girl was molested by a drunken man on Monday night.

The incidents followed last year's violence between Serbian and Croatian supporters, and together they have injured the reputation of what players and fans have long-considered the friendliest of the four grand-slam tournaments.

Tournament director Craig Tiley joined Victorian police superintendent John Cooke to defend the use of capsicum spray on a group supporting Greek player Konstantinos Economidis in his clash with Chile's Fernando Gonzalez.

Offensive chants in Greek and English were heard, leading police to step in. One of the men was abusive to police, and after being asked to control himself threw a punch at a police member.

Mr Tiley said organisers would review security measures at the end of the tournament and also consider a ban on the sale of full-strength beer, as has happened at major cricket matches in Australia.

"The reputation of the Australian Open has been upheld by the fans over the last two days that have come through the gates," Mr Tiley said.

"The poor behaviour of a small group of people, we are not going to tolerate."

Superintendent Cooke, in charge of policing the Open, defended the use of capsicum spray, saying an all-in brawl would have been more likely if it had not been used.

"Our members are not punching bags," he said.

"The members have deployed it for their own safety. Had we not used the spray, had our members been involved in a physical confrontation with that group in that sort of environment, I'm quite sure that we would have had a great deal more injuries to the police and to the spectators."

Superintendent Cooke said some crowd members "should be ashamed" of their behaviour.

He said newspaper reports about children and other crowd members being left "gasping for air" were incorrect.

The ban imposed on the three men applies for the rest of the tournament, and they face trespass charges if they try to return.

The latest incidents come after police announced an extra presence in response to last year's violence. There were also several cases of "upskirting", leading to law changes in Victoria, and a young boy was sexually assaulted.

In a separate incident, a 12-year-old girl was touched on the buttocks on Monday.

Police received a complaint yesterday, and said they were investigating whether a drunk man was responsible.

"The matter was reported to police this morning and the incident is currently being investigated," a spokeswoman said.

Superintendent Cooke said police would "act exactly the same way" if confronted with any more crowd violence.

Police are reviewing CCTV footage of the incident, while mobile phone footage has been circulated on the internet.

Victorian Premier John Brumby promised yesterday the use of capsicum spray would be subject to a full inquiry.